Lean Construction in reducung waste on sites

Applying Lean Construction

Techniques to Identifying and

Reducing Waste in Grinaker-LTA

Building Inland (GLTA)

STANLEY TAVERO GEORGE

Dissertation submitted to Milpark Business School in partial fulfilment

of the requirements of

Master in Business Administration

Johannesburg, March 2010

Supervisor: Sarel Visagie

Declaration

I, Stanley Tavero George, declare that this research report is my own, unaided

work, except as indicated in the acknowledgements, the texts and references. It

is being submitted in partial fulfilment of the requirements of the degree of Master

of Business Administration at Milpark Business School, Johannesburg. It has not

been submitted before, in whole or part for any degree or examination at any

other institution.

Stanley Tavero George

Signed on………………….Day of…………………………………2010

ABSTRACT

This study evaluated the current understanding and attitude towards waste recognition and the tendency to waste reduction within the Grinaker-LTA Building Inland business unit. The principles of Lean Construction were used as a basis for benchmarking the current state and as a tool to take the organization forward in this ever increasingly competitive building construction market.

Two construction sites within Gauteng were used in this study. Employees were asked to respond to questionnaires that were structured to solicit certain information out of them. The collected data was analysed using tables and graphs.

The study showed that there was no conclusive evidence that Grinaker-LTA was either traditionalistic or lean in the way that employees regarded waste on construction sites. However, an important imperative came out that the ability to recognize waste on site does not necessarily prompt action to reduce or eliminate it. Furthermore all five possible sources of waste on site were identified as being likely to be causing waste on sites. This situations reveals that GLTA needs to move towards a more lean position.

This study recommended that Grinaker-LTA should start to scientifically evaluate its waste management programmes if it must stay ahead of the pack because operational efficiency is the answer to today’s profitable organizations. To achieve this goal, there is need for top management commitment, inclusivity, benchmarking and creation of a learning organization.

Finally, it is also recommended that further research be undertaken to understand the organizational behaviour and design the service profit chain.

DEDICATION

To my siblings and friends

ACKNOWLEDGEMENTS

I am extremely grateful to all the people who helped in the successful

production of this dissertation. Firstly, I am deeply appreciative of the

assistance, advice and support given to me by my supervisor, Mr S

Visagie. I also want to thank all the people who took their valuable

time to complete my questionnaire, may God bless you.

Last but not least I would like to thank my partner and friends for

enduring long hours without their loved one as I worked on this project.

List of Abbreviations

CIDB Construction Industry Development Board

GLTA Grinaker LTA Building Inland

JIT Just In Time

TFV Transformation Flow and Value Model

TPS Total Production System

TQA Total Quality Assurance

TQC Total Quality Control

TQM Total Quality Management

TPM Total Productive Maintenance

Table of Contents

1.0 Dissertation Title…………………………………………………………………1

1.1 Introduction……………………………………………………………..1

1.2 Problem Statement……………………………………………………..3

1.3 Purpose and importance of study…………………………………….5

1.3.1 Purpose…………………………………………………...5

1.3.2 Importance……………………………………………..…5

1.3.3 Review of existing literature…………………………….6

1.4 Research objectives……………………………………………………7

1.5 Research methodology………………………………………………...7

1.5.1 Definition and scope of the research study…………...8

1.5.2 Definition……………………………………………….…8

1.5.3 Scope…………………………………………………..…9

1.5.4 Limitations of the research study………………………9

1.5.4.1 Research validity………………………………9

1.5.4.2 Research reliability…………………………….9

1.6 Structure of the dissertation………………………………………….10

1.7 Timelines…………………………………………………………….…11

1.8 Conclusions………………………………………………………….…11

2.0 Related literature review………………………………………………….…….13

2.1 Introduction………………………………………………………..……13

2.2 Comparison to manufacturing……………………………………..…14

2.3 Lean production in manufacturing…………………………………...16

2.4 The new production system…………………………………………..17

2.5 Impact of new production system on construction…………………18

2.6 Impact of new production system in South Africa……………….…19

2.7 The concept of production………………………………………….…19

2.7.1 Transformation…………………………………………...20

2.7.2 Flow concept……………………………………………..21

2.7.3 Value generation concept……………………………….22

2.7.4 Just in time………………………………………………..22

2.7.5 Total quality control………………………………………23

2.7.6 Total productive maintenance…………………………..23

2.7.7 Concurrent engineering…………………………………24

2.7.8 Continuous improvement………………………………..24

2.7.9 Visual management………………………………………25

2.7.10 Value based strategy management…………………….25

2.8 Flows in construction………………………………………………..26

2.9 Construction waste…………………………………………………..28

2.9.1 Introduction……………………………………………..28

2.9.2 Waste and value loss in construction………………..29

2.9.3 Waste and value loss due to quality of works…….…29

2.9.4 Waste and value loss due to constructability………..29

2.9.5 Waste and value loss due to material management..30

2.9.6 Waste and value loss due to non-productive time….30

2.9.7 Waste and value loss due to safety issues………….30

2.10 New concept of waste in production activities……………31

2.11 Lean production model for waste in lean construction….32

2.12 Waste classification…………………………………………35

2.13 Key construction waste causes……………………………39

2.14 Waste and performance in construction……………….…39

2.15 Conclusion ……………………………………………….…39

3.0 Research methodology…………………………………………………….….41

3.1 Method of research……………………………………………….….41

3.2 Profile of respondents…………………………………………….….45

3.3 Hypotheses……………………………………………………………45

3.4 Structure of the questionnaire………………………………………46

3.5 Conclusion…………………………………………………………….47

4.0 Data analysis and interpretation………………………………………………48

4.1 Introduction……………………………………………………………48

4.2 Response………………………………………………………………48

4.3 General waste recognition……………………………………………49

4.4 Waste mitigation scenario……………………………………………52

4.5 Frequency of occurrence……………………………………………54

4.6 Sources and causes of waste……………………………………….56

4.7 Discussion of findings……………………………………………..…57

5.0 Conclusion and recommendations……………………………………………59

5.1 Introduction………………………………………………………….…59

5.2 Relating findings to research objectives……………………………59

5.3 Relating research findings to hypotheses………………………….61

5.4 Recommendations……………………………………………………62

6.0 References………………………………………………………………………66

7.0 Appendix…………………………………………………………………………70

Table of figures

1.1 Breakdown of the scopes of each phase of the research methodology……11

1.2 Gantt chart for approximate duration of research activities…………………14

2.1 Fundamental differences between manufacturing and construction……....17

3.1 Direct waste elements on site…………………………………………………..44

4.1 Response ………………………………………………………………...52

4.2 Classification of respondents …………………………………………………..52

4.3 General waste recognition………………………………………………………54

4.4 Waste mitigation…………………………………………………………………55

4.5 Frequency of occurrences………………………………………………………57

Table of Tables

2.1 Differences between manufacturing and construction……………..……………………….…

17

2.2 Direct waste on site ……….……………………………………………………...44

4.1 Key of waste type………………………………………………………………….52

4.2 Key of waste variable ……………………………………………………………..52

4.3 Matrix of general waste recognition …………………………………………….54

Dissertation Title

Applying Lean Construction Techniques to Identifying and Reducing Waste in

Grinaker-LTA Building Inland (GLTA)

1.1 Introduction

Grinaker-LTA Building Inland is a building construction company based in

South Africa and is part of the listed company Aveng Group. The company

has a long history dating back to the early 20th century and is currently one of

the “big five” construction companies in South Africa.(CIDB, 2004)

The construction business is a key sector in the world economy and more so

for developing countries like South Africa. The industry is probably one of the

longest surviving that has had a slow evolution mainly triggered by advances

in technology. Advances in technology have enabled buildings to be erected

faster and be more complicated in design. The globalization of the world

economy has seen a lot of movement of companies, capital and skills within

the industry. For individual companies this translates to more threats from the

operating environment. Government interventions especially on regulating the

green environment mean that it is not business as usual for most construction

companies. The current downturn in the world economy has resulted in fierce

competition for contracts. For example, the world’s largest destination for

construction work, Dubai, has seen a cut of up to 30% in the amount of

contracts available due to investors suspending projects.( EngineeringNews,

2009)

From its crude beginnings, the construction industry has seen an evolution

where building construction and management has become scientific. Whilst

trying to address endemic problems in the industry such as low productivity,

low client satisfaction, poor health and safety, scholars and practitioners have

developed scientific empirical ways of measuring success in projects. (Leng,

2004). Advances in Total Quality Management and the subsequent

development of the ISO 9000 series are all attempts to ensure that quality

and customer satisfaction are achieved.

However, companies are in business to make profits. According to the centre

for Experiential Education and Shingo (1989), the only way of increasing

profits in a competitive environment is to reduce costs. Most studies in the

construction industry have been centred on introducing new technologies and

speeding up the construction process without much regard for the companies’

bottom line. Recently there has been a shift to Lean construction, a new

paradigm that seeks to optimize the construction process; emulating the

successes in the lean manufacturing processes like the Toyota Production

System (Leng, 2004). The new paradigm is based on the concept, of

conversion and flow process similar to that of the manufacturing industries.

Opportunities for reducing costs are realised through the identification of

wastes and minimising them in parallel to value adding strategies such as

training and new technology. However, the concept of waste is grossly

misunderstood by a lot of construction personnel. It is the pursuit of

eliminating waste that will differentiate companies in the competitive

environment of the construction business. Companies like GLTA that have

over time perfected their systems and are accredited for quality assurance

systems and must move further and broaden the concept of waste so that

they optimize their competitiveness.

Organizations constantly change in response to their external, internal and

temporary environments (Senior, 2002 p.26). Construction has been a slow

evolving industry with the major changes happening due to harnessing new

technology that makes the construction process faster. However, it is time

that softer issues of management be adopted and be widely used to optimize

the conversion and process flow for more productivity, less waste and higher

profits.

1.2 Problem Statement

Grinaker-LTA is one of the “big five” construction companies in South Africa.

Over the years the company has developed cultures and systems that have

made it competitive and have capacity. GLTA is ISO 9001 accredited. This

accreditation helps with the “end” side of the construction process as it

ensures that certain processes are adhered to for quality purposes. However,

the company is still bedevilled by some chronic problems found in

construction such as low productivity and poor health and safety record and a

lot of rework of jobs. There is still need to optimize the construction process at

site level so that the “mean” end of production is efficient as well.

Lean Construction is a new paradigm that has roots in the manufacturing

processes such as the Toyota Production System. According to researchers

and scholars, Lean Construction philosophy is laid on the concept of

conversion and flow process. If a construction process is evaluated as a

conversion and flow process, waste identification opportunities are possible

thereby improving performance of the system. This should be done in parallel

to value adding strategies already in place for the company.

Having joined the group recently, the writer has identified some waste on site

and presumably the same observation may be extended to other similar

construction sites within the company. It is assumed that the concept of waste

is not fully understood and by utilizing techniques of Lean Construction and

education of key construction personnel, further competitiveness will be

induced into the company. There is need to bridge the gap between the

existing practices and the Lean Construction paradigm first. Parameters for

waste measurement, value, cycle variability need to be defined and

understood as well as the examination of the current personnel’s

understanding of waste.

The organization might need to adopt a fine tuning or incremental adjustment

strategy both of which are aimed at allowing the organization to operate more

efficiently and optimize the consistencies between strategy, structure, people

and processes (Senior, 2002). According to the Lean Construction Institute,

the principles lie in taking further the principles of Total Quality Management

for the organization to improve productivity through, Flow and Value

Management, that is, lean design, lean supply, lean assembly, work

structuring and production control. All this is done to reduce waste and finally

increase customer satisfaction

The Lean Construction Institute states that:

Cycle time = Processing + handling + Inspection + Waiting

The old paradigm concentrated on improving processing (Conversion) while

disregarding handling, inspection and waiting waste. Processing is value

adding (conversion), whilst handling, inspections and waiting are non-

essential and therefore regarded as waste that must be minimized.

It is proposed that Koskela’s (1992) Conversion and Flow Process Model be

used along with the principles of Lean Construction to evaluate the current

state of waste recognition and mitigation for GLTA as well as to recommend

the road map to compliance.

1.3 Purpose and importance of the study

1.3.1 Purpose

The study is intended to evaluate the current understanding of Lean

Construction within GLTA in reference to waste management. The idea is to

gauge how lean the organization is and map a road for compliance. The

concept of lean construction will be proposed as a solution to see waste

recognition and reduction as a group strategy to improve productivity and

profitability

1.3.2 Importance

Given the current global economic trends it is important for GLTA to position

itself in a very competitive position if successes of the past are to continue

being realised. The group must take a leading role among its peers in the

industry and move the South African construction industry forward in the new

construction management paradigm. According to the centre for Experiential

Education and Shingo (1989), the only way of increasing profits is a

competitive environment is to reduce costs. This fact is an assumed known;

however, it has been scientifically elusive to fathom. Lean Construction

principles are meant to assist in improving the conversion and process flow of

the building process. GLTA has a department of continuous improvement and

this study is meant to assist in proposing Lean Construction as an alternative

solution to the group’s endeavours. This study will set up the ground work for

future thorough studies and implementation of lean construction techniques in

GLTA

1.4 Review of existing Literature

Ballad and Howell (1998) defines construction as the design and assembly of

objects fixed in place. Koskela and Huovila (1997) proposed 3 ways of

conceiving a construction processes: conversion of inputs into outputs, flow of

information and materials and generating value for the customer. However,

Ballad and Howell argue that this view of the conversion process has

dominated thinking and practice for a long time. Moving towards Lean means

consideration of value and flow processes.

Abdelhamid (2004) of the Lean Construction Institutes summarizes the history

of thinking effectively. The first stage was construction-as-usual, dominated

by fragmentations of responsibility between, the customer, management and

the artisans on site. Ineffective communication and non-alignment of goals

resulted in a lot of waste and less customer satisfaction. The second stage

saw scholars and practitioners ushering in new improvement initiatives that

included, Value engineering, Design and construct, Partnering, Total Quality

Management, Health and Safety and many more. These new initiatives were

broadly centered on productivity improvement mainly through new

technology. However there was less elimination of waste resulting in less

customer satisfaction still.

The new thinking is Lean Construction that basically involves flow and value

management. This all entails lean design, lean supply, lean assembly, work

structuring and production control. This thinking also recognizes the seven

wastes that must be minimized as: correction, motion, overproduction,

conveyance, inventory, processing and waiting. According to scholars, this

thinking and practice eliminates waste and results in better customer

satisfaction and in turn more profit for the construction company.

A thorough review of literature shall be done in subsequent chapters that will

show the history of production management that culminated in the concept of

Lean Construction.

1.5 Research Objectives

The research is aimed at one organization but forms a basis for further

research in the subject to the construction industry in South Africa.

For the sake of this study, the major objectives are:

To examine the general perception and attitude towards and practice of

lean construction principles within GLTA.

Examine the extent of problems arising from waste identified in the current

scenario

Identify the sources of waste

Study the possible improvements aimed at eliminating waste

1.6 Research Methodology

Table 1.1: Breakdown of the scopes of each phase of the research

methodology

Formulate Problem

Statement

Identifying an area of study and research

of current literature so as to understand the

subject matter.

Finalizing the research topic

Research Design A quantitative research approach will be

adopted for this study

The survey will be conducted within two

construction sites of GLTA

A questionnaire shall be designed and

structured in such a way that the factors and

variables relevant to the study are captured

Data collection and

processing

Data will be collected by hand delivered

questionnaires as the population is

composed of colleagues

Data will be sorted according to level of

responsibility of the respondents within the

company

Data analysis Statistical analysis will be done through

the descriptive and inference statistics

The significance of the factors and

variables will be compared to the problem

statement

Conclusions and

recommendations

A comparison of the outcomes of the

data with the problem statement will be

done.

Constructive recommendations will be

drawn based on the objectives of the study

Research report Write up of the final draft to be submitted

1.6.1 Definition and scope of the research study

1.6.2 Definition

This study is aimed at applying the principles of Lean Construction to GLTA

Building Inland. An evaluation of the current extent of practice of the

principles and wastes identified shall be done and based on that,

recommendation on the way forward in the implementation shall be

suggested.

1.6.3 Scope

The study is limited to GLTA Building Inland construction sites in Gauteng

Province

Primary data will be collected from site personnel who are directly involved

in planning and executing building work.

1.6.4 Limitations of the research Study

There are certain limitations to this research as the writer wishes to highlight:

1.6.4.1 Research validity

GLTA has several business units based on province and speciality. This

study will be limited to GLTA Building Inland that is based in Gauteng

Province. The outcomes of the study may be biased towards building

construction projects and to a certain culture created over the years within the

Inland business unit. It is recommended that further extensive research be

carried out throughout the group to get a more representative view of the

performance of the group.

1.6.4.2 Research reliability

The subject of lean construction is relatively new in South Africa, thus there

may be very little attention at documenting parameters of variability on the

various projects undertaken. This might affect the understanding of questions

by respondents and hence the consistency of the results obtained.

1.7 Structure of the Dissertation

Chapter 1, Introduction:

This chapter covers the overall perspective of the research study such as

background to the study, problem statement, research aims, scope and

objectives, methodology and limitations of the study

Chapter 2, Problems in Construction and the trends in Improvement

Strategies:

This chapter will examine the problems faced in construction and the various

thinking and practices that have been developed over the years to try and

resolve the problems. The concept of Lean Construction will be introduced.

Definition of waste and models for waste minimization shall be discussed as

well.

Chapter 3, Research Methodology:

This chapter shall focus on the design of the questionnaire, formulation of the

hypothesis and how they are to be tested. A general overview of the statistical

analysis to be applied shall also be discussed

Chapter 4, Data Analysis and Interpretation:

The results from the questionnaires shall be interpreted with reference to the

hypothesis and the research objectives.

Chapter 5, Conclusions and Recommendations:

This chapter shall conclude the study based on the findings. The findings

shall be used to provide a strategic solution to the problems identified in

GLTA and to provide a roadmap for the formalisation on the practice in the

company

1.7Time lines:

Table 1.2: Gantt chart for approximate duration of research activities

Description Drn Week

    Wks 2 2                               1 Literature review 8                          2 Questionnaire design 4                          

3Send out questionnaire 4                          

4 Data analysis 6                          

5Conclusions and recommendations 4                          

6 Drafting final report 4                          

1.8 Conclusion

It is not easy to differentiate strategies among construction companies as there are so

many similarities among them. However, company cultures and practices are

different. Profitability within companies emanates from internal efficiencies. It is

imperative that GLTA embark on a scientific evaluation of its activities to build

efficiencies that will give it an edge over their competition with the ultimate goal of

profitability and customer satisfaction. To this end, this study will attempt to look at

one aspect of operations where the company can improve itself and also to act as a

propellant for further in-depth studies to be carried out within the group.

2.0 Related Literature Review

2.1 Introduction

According to the Construction Industry Indices (CIDB, 2007) there was 26%

customer dissatisfaction, 33 quality problems that were not acceptable, 25%

defects that were not acceptable and safety remains a concern with the

construction industry that recorded the second highest fatalities in the

workplace after mining between the year 2006 and 2007. The CIDB quotes

the M4I as saying “Clients in construction want their projects delivered on

time, on budget, free from defects, efficiently, right the first time, safely and by

profitable companies. Regular clients expect continuous improvement from

their construction companies to achieve a year on year reductions in project

cost and reduction in project cost”. This indicates that customer satisfaction is

also achieved through the organization’s internal processes. According to

research carried out by Koskela (1993) on studies done in Sweden, it was

discovered that there is a lot of none value adding activities in construction

and associated costs as shown below:

Quality (non-conformance) 12%

external quality costs (during facility use) 4%

lack of constructability 6-10%

poor materials management 10%

excess consumption of materials on site 10%

time used for non-value adding activities on site 66%

lack of safety 6%

Problems in Construction

There are endemic problems in construction such as poor work quality, poor

safety practices, low productivity and others that are well known. Most of

these problems have been left unattended for a long time because of the

inherent belief that they cannot be solved. These problems are attributed to

the nature of the industry, such as one-of a kind, once off, in situ, temporary

multi-organization and over time have not been given attention and are simply

factored in on pricing projects. Conclusions from some scholars are that it is

the fragmented nature of the industry, lack of coordination and

communication, adversarial contractual relationships and lack of customer

focus that inhibit industry performance. Scientific study of the industry has

been difficult as appropriate models are difficult to draw. When compared with

manufacturing where activities are controlled and routine, construction has

got a lot of variables that make it difficult to streamline information flow and

waste management. This is exacerbated by use of temporary labour, moving

machinery and other factors that cannot be easily predicted and planned for.

However some of these can be overcome by applying new flow designs,

improving the existing and use of new technology (Alarcon, 1994). The new

thinking is that the solution lies in the organization, planning, allocation and

control of resources, processes and technologies for the achievement of

higher productivity

2.2 Comparison to Manufacturing

The Manufacturing Industry has been a source of reference for improvements

in construction, although some believe that both industries still learn from one

another (Howell et al, 1998) Efforts to transfer the successes of the

manufacturing industry to construction have been done, for example the use

of new technology and process adoption, industrialization, prefabrication and

modularization and computer integrated construction. According to Koskela

(2000), there has been no major improvement in construction due to this

adoption mainly due to the fundamental differences between the two

industries as indicated in the Table 2.1 below

Table. 2.1 Fundamental differences between manufacturing and construction.

Source: Leng (2004), The application of lean thinking to reduce waste in

construction flow process)

Start of manufacturing Start of construction

What Highly defined Evolving

How Highly defined

Ops plan is in great

detail based on many

trials

Primary sequence of

tasks is inflexible and

interdependency is

documented and

approved

Positions in sequence

determines skills

requirement

Partly defined but

details unexamined

Extensive planning

still remains by hard logic

Interdependencies

due to conflicting

measurements, shared

resources and

intermediate products only

partly understood

Skills vary in all areas

Assembly objectives Produces one of a finite

set of objects with clear

definition from the

beginning

Make one only with details

that are not clearly known

from the beginning

Improvement strategy Rapid learning from the

first units preparing for

production line

Rapid learning during both

planning and early sub

assembly cycles

In the late 1980’s there was a new trend in production that caught the

attention of academics and construction practitioners. The fundamentals of

this new development are that new industries are “lean”, using less of

everything and these changes have been due to application of a new

philosophy called Lean Production. Among the pioneers in the academic

circles to try and adopt this new philosophy are Koskela and Alarcon. Koskela

(1992) identified the dominance of the “conversion” thinking in construction

and argued for the replacement of it with the “conversion-flow” thinking.

Alarcon (1995) also identified this fact and argued that performance could be

improved by waste identification and reduction in parallel to the value adding

strategies. The challenge is identifying and measuring waste as an effective

tool to improve production systems as it points out areas that need attention.

Waste modelling and measurement assist with process management since

operational costs can be properly modelled and information used for

decentralised control

2.3 Lean Production in Manufacturing

Traditional production thinking after the industrial revolution never went

beyond the concept of production as a transformation process, thereby

ignoring the flow processes that are part of production and inhibited

improvements in the system

There was a paradigm shift in the 1950’s when Ohno, a former Toyota

executive set out to develop a new production system called the Toyota

Production System (TPS). The basic idea was to adopt strategies that are

based on downstream demand in the production chain. This maintained a

planned pace of production and avoided unnecessary inventories. According

to Conte and Gransberg (2001), the TPS goal is to achieve continuous

production by adopting monitoring measures for each process aiming to

reduce waste. Elimination of inventories and other waste through small lot

production, reduced set up times, semi-autonomous machines, co-operation

with suppliers and other techniques

The off-shoot from this system is termed Just-In-Time (JIT) and has

contributed to major improvements in productivity in manufacturing from the

1970’s (Koskela 2000). Simultaneously quality was attended to through

consultants like Deming, Juran and Feigenbaunm. This was a statistical

method of quality assurance that was refined by industrial engineers through

trial and error. Other philosophies emerged such as Total Quality

Management (TQM), Value Based Management and Concurrent Engineering

but where all based on the same principles viewed from different angles.

At the beginning of the 1990’s, a new production philosophy emerged known

by several names (Lean production, world class production, new production

system). It was mainly applied in manufacturing but has diffused to services,

administration and product development. The latest trend is for a leaner

production chain through all stages of production that must include the whole

value chain. Krafcik coined the name lean to emphasizes less of everything,

less people, less materials and lower cost. Womack and Jones (1996)

suggested that lean thinking provides production processes a way to specify

value, line up value adding processes in best sequence, conduct them

without interruption and more effectively.

2.4 The New Production system

All production systems consist of Conversion and Flow (waiting, moving,

inspection) processes. Conversion adds value while flow does not. Value is

realised through customer satisfaction and the money paid for the

goods/services. Profit is realized through streamlining flow processes and

making conversion more efficient. According to Koskela (1992), traditionally

the production system compounded conversion and flow as if it were all value

adding, resulting in complex, uncertain and confused flow processes,

expansion of non-value adding activities and reduction of value adding output.

Enton (1994) summarized the applicability of lean thinking in construction

process as:

1. Analysis and separation of conversion and flow processes

2. Conversion activities go through QC, QA and TQM

3. The flow activities should find ways of simplification, elimination

and automation in order to reduce them

2.5 Impact of new production system on construction

Since the 1990’s, the new production system has been applied in the US and

Europe recently on a regular basis where a lot of work is being done by

academics and practitioners to use it to improve the construction industry.

Koskela (1992) identifies the dominance of the conversion thinking in

construction and argues that this should be replaced by the Conversion-Flow

thinking that runs along the new production system. Howell (Civil Engineer)

and Ballard (Researcher), have put forward the concept of Lean Construction

by seeing potential for applying the general principles set by Koskela. The

Lean Construction Institute says that Lean Construction is a production

management based approach to project delivery by maximizing value and

reducing waste. Lean Construction has gained momentum since 1993 and

new curriculum especially at post graduate level is now being introduced to

students. A nationwide “Rethinking Construction” movement in the UK is

taking place led by a report from Sir John Egan in 1998. The essence of the

Egan report is to set targets for improvement on a year-to-year-basis of

productivity processes through waste reduction such as time, cost, rework

and accidents and increasing value in quality, finished products, etc.

2.6 Impact of the new production system in South Africa

Following the trend of manufacturing being the predecessor of many

production improvement strategies, Lean production is mainly applied in

South Africa’s manufacturing industry. There are many initiatives in tertiary

institutions to permeate the knowledge to industry and one such example is

the Lean Development Group base at Nelson Mandela Metropolitan

University (www.nmmu.ac.za). There is no clear evidence of a deliberate aim

to apply lean production methods in construction production. However, most

construction firms apply one or more of the predecessors of lean thinking

especially in quality assurance such as Value Engineering, TQM and QA. The

Government in its quest to provide affordable housing to the population, has

embarked on a quest to find technology and methodologies that provide fast

and cheaper erection methods for low cost housing. One such initiative is

through the Moladi modular houses that are created from low strength

concrete (www.moladi.com).

Given that lean production in construction is a relatively new concept and is

still in its infancy in Europe and the USA, it is going to take time for the new

thinking to filter in South Africa and be appreciated as the solution to

improving the current industry practices.

2.7 The Concept of production

Koskela did a historical analysis of the production concept and revealed that

there are 3 sub-concepts to production and that the whole concept could be

identified and separated into Transformation, Flow and Value generation

(TFV Model)

2.7.1 Transformation

This has been the dominant theory since the beginning of the 20th century

where production was viewed as transformation of inputs to outputs.

Production management is there fore the decomposition of transformation

into elementary tasks and transformations, acquiring the inputs to these tasks

with minimal costs and the carrying out as efficiently as possible of these

tasks. The core principle is “the decomposition” of sub- transformations into

smaller and more manageable tasks for individuals”

Production Process

Sub-process A Sub-process B

Products

MaterialsLabour

Figure 2.1. Production as a transformation process.

Source: An exploration towards a production system and its application to

construction, Koskela, Lauri (2000)

The total cost can be minimized through minimization of each sub-

transformation processes. The assumption is that sub-processes are

independent of each other and cost reductions can be achieved through cost

management of each sub-process. Furthermore, it is recommended that it is

advantageous to insulate the production process from the external

environment through physical or organizational buffering. The assumption is

that the transformation process is so important that it is necessary to insulate

it from the erratic external environment

Shortcomings of the transformation concept

Transformation concept is conventionally widely-accepted in terms of

production mainly due to its sufficient power to model reality, and excellent

power of various tools to analyze and control of production in an easy and

simple way. However it over simplifies processes and tends to undermine the

full potential to optimize the efficiency of production process.

The transformation concept has its shortcomings. By focusing on

conversions, the model abstracts away physical flows between conversions.

The flows have cost and time variables that must be taken into account in the

overall production process.

2.7.2 Flow Concept

Time is introduced as an input (or resource) in production and therefore the

main focus is in the amount of time consumed by the total transformation and

its parts by aiming for the production improvement at shortening of the total

time of production. Time is consumed by two types of activities in the overall

production flow which are transformation activities and non-transformation

activities. Non-transformation activities are unnecessary and the less of them

is better and best if there are none of them.

The principles of eliminating the flow activities include reducing the share of

non-value-adding activities, reduce lead time and variability and providing

practical ways in implementation such as simplifying by minimizing the

number of steps, parts and linkages, increase flexibility and increase

transparency.

2.7.3 Value Generation Concept

The underlying concept is the satisfaction of the customer. This concept

covers external needs and the production system is structured in such a way

that customer needs are taken into account. Production management equates

to translating these needs accurately into a design solution, and then

producing products that conform to the specified design.

It focused on control of the transformation and flow, namely control for the

sake of the customer and it is important to highlight that the value generation

concept does not focus on any particular aspect of physical production like

transformation and flow model do but rather on its control in securing value

generated for the customer.

2.7.4 Just In Time (JIT)

JIT is mainly applied in Industrial Engineering as initiated at Toyota car

factories in the 1950’s. The principal idea in the approach was the reduction

or elimination of inventories. This, in turn, led to other techniques that were

forced responses to coping with fewer inventories such as lot size reduction,

layout reconfiguration, supplier cooperation, and set-up time reduction. The

pull type production control method, where production is initiated by actual

demand rather than by plans based on forecasts, was introduced.

2.7.5 Total Quality Control (TQC)

TQC is a technique that is founded on the use statistical methods to control

quality through inspection. The technique was started in Japan and has

evolved from mere inspection of products to total quality control of the

organization through:

The focus has evolved from an inspection orientation (sampling

theory), through process control such as Fishbone Diagram, Control Chart,

Pareto Chart, Run Graphs, Histogram, Flow charts or Check sheets &

Correlation Diagram) to continuous process improvement through the new

seven tools, that is, Affinity Diagram, Interrelationship Diagraph, Tree

Diagram, Matrix Diagram, Prioritization Grid, Process Decision Programme

Chart and Activity Network Diagram), and presently to designing quality into

the product and process (Quality Function Deployment).

2.7.5 Total Productive Maintenance (TPM)

Total Productive Maintenance is a comprehensive program to maximize

equipment availability in which production operators are trained to perform

routine maintenance tasks on a regular basis, while technicians and

engineers handle more specialized tasks. The scope of TPM programs

includes maintenance prevention (through design or selection of easy-to-

service equipment), equipment improvements, preventive maintenance, and

predictive maintenance (determining when to replace components before they

fail).

2.7.6 Concurrent engineering

Concurrent engineering is a cross-functional, team-based approach in which

the product and the production process are designed and configured within

the same time frame, rather than sequentially. Ease and cost of

constructability, as well as customer needs, quality issues, and product life

cycle costs are taken into account earlier in the development cycle. The main

ideas about concurrent engineering is to achieve an improved design process

characterized by rigorous up-front requirements analysis, incorporating the

constraints of subsequent phases into the conceptual phase, and tightening

of change control towards the end of the design process.

2.7.7 Continuous improvement

Continuous improvement is a never-ending effort to expose and eliminate root

causes of problems; small-step improvement as opposed to big-step or

radical improvement. A Continuous Improvement strategy involves everyone

from the very bottom to the very top, the basic premise being that small

regular improvements leads to a significant positive improvement over time.

The main goal of the continuous improvements is to affect the mindset as well

as achieve the improvements of the techniques. In this case, everyone

pitches in and receives training in the appropriate skills; responsible for their

own efforts, areas and progress of their teams and the employees will

continuously suggest improvements to meet quality, cost and delivery target

improvements. The key idea of continuous improvement is to maintain and

improve the working standards through small, gradual improvements.

2.7.8 Visual management

Visual management is an orientation towards visual control in production,

quality and workplace. The core principal of visual management is the ability

to understand that, with a quick look at the shop floor what orders are being

done, if production is ahead, on par or behind and what needs to be done

next. No orders are missed or lost and every one knows if they are behind or

ahead on the day’s production. Shop floor staff will take on more self-

managing responsibility with this method as day-to-day decisions are handled

on the shop floor. Generally this method is implemented on large boards next

to particular areas on the shop floor, and as much information is shared as is

feasible, ranging from maintenance to production targets and production

output to injuries.

2.7.10 Value based strategy Management

Value based strategy management is a customer-oriented, in contrast to

Competitor oriented approach toward overall production process. It is a

continuous improvement to increase customer satisfaction by conceptualizing

and articulating value as the basis for competing.

Principles of lean production for production improvement

FLOW C OMPR ESSION

Reduce the share of non-val ue addi ngacti viti es

Reduce variability

Reduce the cycl e ti me

Simplify by mi ni mizing s teps

FLOW D YNAM IC AND FLEXIBILITY

Increase output value

Increase output flexi bility

Increase process transparencybenchmar king

FLOW STABILIT Y AND CONTROL

Focus control on the complete process

Build conti nuous i mpr ovement i nto sys tem

Bal ance fl ow i mprovement with conversionimpr ovement

Figure 2.2 Summary of principles of lean production:

Source: Leng (2004), The application of lean construction to reduce waste in

construction process flow

2.8 Flows in construction production

Ballard and Howell (1998), concluded that the production in construction is

assembly-type, where different materials flow to the end product. Koskela

(2000) suggested that there are three types of flow associated with

construction, namely material flow (transportation of components site for

particular installation), location flow (movement of trades on site) and

assembly flow (sequence of work)

There are at least seven resource flows that generate the construction task as

illustrated In Figure 2.3 below. Many of these resource flows are of high

variability, and thus the probability of a missing input is considerable.

For instance, it is not uncommon that detailed drawings are still lacking at the

project start date. Latent errors in drawings will emerge as problems during

construction on site. External conditions also form one specific source of

variability. The productivity of manual labour is inherently variable, and the

availability of space and connecting works is dependent on the progress of

tasks of previous trades. The degree of variability is higher in construction

production compared to manufacturing production.

Koskela (2000) says that ‘realization of tasks depends on flows, and progress

in turn is dependent on realization of tasks’, basically meaning that planning

and controlling production is very important and tasks and flows have to be

considered in parallel in production management.

TASK

Construction design

Materials

Workers

Equipment

Space

Connecting works

External conditions

Figure 2.3 Flows in Construction.

Source: Koskela (2000), The preconditions of a construction task

2.9 Construction Waste

2.9.1 Introduction

An inclusive definition of waste is all activities and processes that produce

cost directly or indirectly or do not add value. Waste is generally measured in

cost or/and opportunity cost. Some wastes are related to efficiency and are

difficult to measure because the optimal performance is not usually known.

The association of only physical material as waste in construction has over

the years caused a lot of other waste to go unquantified and hence neglected.

This is clearly due to the dominance of the conversion model thinking that

describes processes as conversion from one to another.

2.9.2 Waste and value loss in construction

Koskela (1992), stated that there has never been any systematic attempt to

observe all wastes in a construction process but nevertheless, partial studies

can be used from various countries to indicate the order of magnitude of non

value-adding activities in construction. He summarized some of the findings

as follows:

2.9.3 Waste and value loss due to quality of works

Unacceptable quality of work and nonconformance costs can be very high

due to re-work. It is estimated that these cost are on average 10-20% of the

project cost. In various studies conducted in Europe and USA it was noted

that the causes of poor quality of work result from design (46%), construction

(22%) and material (15%). Deviation costs amount to an estimate of 12% as

studied in the USA mainly due to design related issues. Quality costs are also

incurred by the customer during facility use.

2.9.4 Waste and value loss due to constructability

Constructability is the capability of a design to be constructed. Good designs

should take into account the constraints and possibilities of the construction

process. Good constructability makes costs savings in time, materials and is

good for controlling variability. It is cost effective for a project if the production

process utilizes off-the-shelf materials.

2.9.5 Waste and value loss due to material management

According to Lend (2004), some researchers such as Bell & Stukhart have

estimated that 10 - 12% savings in labour costs could be produced by

materials-management systems. Furthermore, a reduction of the bulk material

surplus from 5 - 10% to 1 - 3% would result from a better material

management practice. Besides that, some researchers also reported that

savings of 10% in materials costs can be achieved from vendor cooperation

in streamlining the material flow.

2.9.6 Waste and value loss due to non-productive time

Workers’ time is not usually utilized in activities that add value. All the

estimation given from the researches compiled by Koskela, the average

distribution of working time used in value-adding activities ranging around

30% to 40%. Oglesby and his co-author estimated around 36% in 1989 while

Levy in 1991 claimed that the average share of working time is 31.9 % in the

United States. Leng (2004) indicates that similar figures from other countries

but some other researches did show a greater variance in percentage. For

example, the average distribution of working time of the 17 observed building

projects survey in Chile conducted by Serpell, et al. (1995) during 1990 and

1994 shows that the minimum value of productive work was 35% and the

maximum was 55%.

2.9.7 Waste and value loss due to safety issues

According to Levitte and Samelson(1988), in the USA, safety-related costs

are estimated to be 6 percent of total project costs.

2.10 New concept of waste in production activities

In the new production paradigm, waste is defined more broadly than its usual

limited scope as any inefficiency that results in the use of equipment,

materials, labour, or capital in larger quantities than those deemed necessary

in the production of a construction project. Waste includes both incidences of

material losses and the execution of unnecessary work, which generate

additional costs but do not add value to the product (Koskela 1992). Waste

may also be defined as any losses produced by activities that generate direct

or indirect costs but do not add any value to the product from the point of view

of the client. Pioneers of Lean production, Toyota, see waste as “Anything

that is different from the minimum quantity of equipment, material, parts and

labour time that is absolutely essential for production.”

The above definitions of waste clearly allude to the fact that waste must be

seen from an activity point of view and not from aggregate inputs such as

material, machinery and labour as the traditional thinking focuses on. Lean

thinking is essentially an extension of the traditional thinking that covers items

that hitherto have not been studied in detail and exposed as stand-alone

waste items. By delving deeper and into more detail on the basis of activities,

Lean Thinking digests construction production into smaller molecules that

help to understand the causes and losses due to waste. It also becomes

easier for practitioners to have specific targets for improving the production

system. There is opportunity to improve production in two ways using the

Lean Thinking approach. The first is to increase efficiency of value adding

activities and the second is to eliminate or reduced waste. From a business

perspective, this increases the bottom line of the organization, that is, more

profit is realized.

There is also a very big benefit to construction production that was not so

obvious using the traditional approach. Using lean thinking, the construction

project is viewed as one production system. This means that customer

satisfaction becomes the primary objective. Instead of concentrating on single

activities as points of focus, total project cost and duration become the single

most important goal. Coordination will be achieved through the central

schedule whilst smaller sections are managed by persons who are aware of

the project goals and work together for the achievement of that goal.

2.11 Lean Production Model for Waste in Lean Construction

The Lean production model in construction should be based on the

Conversion-Flow model that has an ultimate goal of reducing waste in any

production system. Production is a flow that creates value through conversion

processes and is a function of cost, time and value. In other words, lean

production seeks cycle time reduction, waste elimination, zero defects and

flexible output. The parameters that are variable in the model need to be

measurable and standards set for continuous evaluation of the efficiency and

performance.

Koskela (1992) proposed a conversion-flow process model, in which

production is conceived as a flow of materials and information through four

types of stages: transport (moving), waiting (delay), processing (conversion),

and inspection.

Moving waiting Process A inspection Moving

scrap

Figure 2.4. Koskela’s Flow Process Model (Koskela, 1992)

This model distinguishes between value-adding and non value-adding

activities. The model concentrates on the process flow rather than the

exchange among the processes. As a rule in this model, only processing

activities are value-adding activities and the rest are waste and reducing their

share in the process is the target for continuous improvement.

Serpell et al. (1995) have proposed an open and dynamic construction

process model as described in Figure 3.7 below. The model presents the

construction production process that is linked to its external environment.

Some variables in the external environment are controllable and some are

not.

Flow and Process management

Conversion process

productsExternal flows

Controllable area

Internal flows

Flow regulation

feedback

Operational methods

Non controllable area

Environment

Figure 2.5 Model of the construction process.

Source: Serpell (1995)

Flow and conversion management are responsible for making the decision

that define the performance of the system. Flows are the inputs to the system

that may be separated in two types, resources (labour, materials and

construction equipment), and information. There are two types of flows as

portrayed in the model. External flows are usually uncontrollable, for example,

suppliers’ provision of resources and design information. Internal flows are

usually controllable, for example, materials from a warehouse. Conversion

activities transform the flows into finished and semi-finished products. The

methods used in this activities decided by the flows and conversion

management. Products are results of conversion activities.

2.12 Waste classification

Scholars and practitioners acknowledged that there are many non-value

adding activities during the design and construction process and the majority

of these wasteful activities consume time and effort without adding value for

the client. From the inception of a construction project, Construction

Managers have to deal with many factors that may negatively affect the

construction process, producing different types of waste

Formoso, et al. (1999), commented that there is an acceptable level of waste,

that can only be reduced through a significant change in the level of

technological development. Based on the ratio of prevention investment cost

over the cost of waste itself, they have classified wastes into two general

groups, that is, Unavoidable waste (or natural waste), in which the investment

necessary to its reduction is higher than the economy produced, The

percentage of unavoidable waste in each process depends on the

organization and on the particular site, since it is related to the level of

technological development. The second is avoidable waste, where the cost of

waste is significantly higher than the cost to prevent it.

Waste can also be classified according to its origin, that is, the stage that the

main root cause is related to. Although waste is usually identified during the

production stage, it may also be originated by processes that precede

production, such as materials manufacturing, training of human resources,

design, materials supply, and planning.

The most classical waste classification according to lean production paradigm

is perhaps the classification done by Shigeo Shingo. He proposed the

following waste classification whereby waste was classified by its nature,

based on the Ohno’s framework of Toyota Production System:

1. Waste due to overproduction

2. Waste due to wait periods

3. Waste due to transport

4. Waste due to the system itself

5. Waste due to stock

6. Waste due to operation

7. Waste due to defects

Formoso, et al. (1999) gave further clarity on waste classification based on

studies done on construction site in Brazil. His classification is meant to assist

managers to understand the different forms of waste, why they occur and how

they can be avoided or reduced.

Overproduction: related to the production of a quantity greater than required

or earlier than necessary. This may cause waste of materials, man-hours or

equipment usage. It usually produces inventories of unfinished products or

even their total loss, in the case of materials that can deteriorate. A classic

example is the overproduction of mortar that cannot be used on time.

Substitution: is monetary waste caused by the substitution of a material by

a more expensive one that has an unnecessary better performance, the

execution of simple tasks by an over-qualified worker; or the use of highly

sophisticated equipment where a much simpler one would be enough.

Waiting time: related to the idle time caused by lack of synchronization and

levelling of material flows, and pace of work by different groups or

equipments. An example would be a gang waiting one operation to be

complete before they can start working.

Transportation: concerned with the internal movement of materials on site.

Excessive handling, the use of inadequate equipment or bad conditions of

pathways can cause this kind of waste. It is usually related to poor layout, and

the lack of planning of material flows. Its main consequences are: waste of

man hours, waste of energy, waste of space on site, and the possibility of

material waste during transportation.

Processing: related to the nature of the processing (conversion) activity,

which could only be avoided by changing the construction technology. For

instance, concrete is wasted if placed in confined spaces using a bucket.

Inventories: related to excessive or unnecessary inventories which lead to

material waste (by deterioration, losses due to inadequate stock conditions on

site, robbery, vandalism), and monetary losses due to the capital that is tied

up.

It might be a result of lack of resource planning or uncertainty on the

estimation of quantities.

Movement: concerned with unnecessary or inefficient movements made by

workers during their job. This might be caused by inadequate equipment,

ineffective work methods, or poor arrangement of the working place.

Production of defective products: it occurs when the final or intermediate

product does not fit the quality specifications. This may lead to rework or to

the incorporation of unnecessary materials to the building , such as the

excessive thickness of plastering. It can be caused by a wide range of

reasons: poor design and specification, lack of planning and control, poor

qualification of the team work, lack of integration between design and

production.

9. Others: waste of any nature different from the previous ones, such as

burglary, vandalism, inclement weather, accidents, etc.

Waste that is time based is difficult to model because there are no optimal

efficiencies to compare to. Instead of classifying the waste of productive time,

Serpell et. al (1995) broke down those wastes factors in relation of work

categories.

1. Productive work (value-adding activities)

2. Contributory work (non value-adding activities but essential for conversion

process): Those contributory work which are classified as waste include

examples such as transporting, instruction, measuring and cleaning

3. Non-contributory work (non value-adding activities): Those non contributory

work which are classified as waste include waiting, idle time, travelling,

resting, physiological needs, and rework

2.13 Key construction waste causes

Understanding the causes of waste would help in reducing or eliminating

them from the process loops. To work out a continuous improvement strategy

in reducing and eliminating those wastes in construction processes, the origin

of the waste itself has to be identified. Some of the key areas that cause

waste are administration processes, use of resources and information

systems.

2.14 Waste and performance in construction

Modelling and evaluation of wastes and performance in construction projects

is a challenge. Several models and procedures have been proposed for the

evaluation of project performance at site and project level. Some of these

models focus on prediction of project performance while others focus on

measuring. Traditional models offer only a limited set of measures as most of

them limit their analysis to a number of measures such as cost, schedule, or

productivity (usually labour productivity).

The introduction of new production philosophies in construction requires new

measures of performance such as waste, value, cycle time or variability.

Scholars have characterized performance in a broad definition as seven

criteria on which management should focus its efforts on as discussed and

that is namely effectiveness, efficiency, quality, productivity, quality of work

life, innovation and profitability.

2.14 Conclusion

There are endemic problems in the construction industry including waste that

have been attributed historically to the nature of the product, which is, once off,

in- situ and composed of many variables. There has been a drive to steer the

industry towards a manufacturing production kind of scenario where

management and production principles are systematic and scientific. To this end

a new system of thinking called Lean Construction has been put forward to

challenge the conventional thinking that regards construction as a conversion

only process but also to include the flow part of the process. There a lot of

opportunities to recognize waste using Lean Construction models whose aim is

to eventually eliminate or minimize waste. Using Lean Construction models is

both systematic and scientific. The use of the new thinking coupled with other

strategies within organizations is aimed at waste reduction and hence increased

efficiency. It is there fore possible to use the Lean construction models within

GLTA to test waste recognition and mitigation, sources of waste and to

compartmentalize the characteristics of waste.

3.0 Research Methodology

3.1 Method of research

The purpose of this academic research is to find out the degree of awareness

and recognition of waste on site using the Lean Construction process-flow

model as a yardstick. The study will also try to search for the attitude towards

waste by site construction personnel, that is, whether there are deliberate

steps taken of preventing and averting waste should it be recognized. Site

staff that includes foremen, site engineers and managers will be targeted for

this study.

The research is based on a quantitative and deductive approach that requires

the use of a structured questionnaire that seeks to elicit certain variables that

will be used for evaluation. Fortunately for this study that was limited to a

single business unit of Grinaker-LTA, responses could be obtained from the

whole targeted population. There would be no need for probability sampling in

this case (Saunders et al, 2007). Critical realism will be used to study the

current situation regarding practice and attitude so that meaning can be

extracted according to the model for evaluation. It is also hoped that given

that the company has a long history, there might be subjectivity that will

emanate from the acquired culture and that would subsequently point directly

to the root of some of the anticipated challenges.

This research was postulated around Lean Construction techniques that

recognize waste in construction through the process-flow models as

suggested by Koskela (1992) and Serpell et al. (1995). Waste is categorized

into three, that is, direct conversion waste, non-contributory time waste and

contributory time waste and each category has 9, 7 and 3 identified wastes

respectively as tabulated below in Table 3.1

Table 3.1. Direct waste elements on site

Source: Leng. “The application of lean construction to reduce waste in the

construction process flow

Direct conversion

waste

Non-contributory

time waste

Contributory

time waste

1 Over

allocation/unnecessary

equipment on site

Waiting for others to

complete work

before

commencement of

the next task

Time for

supervising

and inspection

of works

2 Over

allocation/unnecessary

materials on site

Waiting for

equipment to be

delivered to site

Time for

instruction and

communication

between

different tiers

of workers

3 Over

allocation/unnecessary

workers on site

Waiting for materials

to be delivered to

site

Time for

transporting

workers,

materials and

equipment

4 Unnecessary

procedures and

working protocol

Waiting for specialist

skills to arrive on site

5 Material loss/stolen

from site

Waiting for

clarification and

confirmation from

consultants or client

6 Material

deterioration/damage

during construction

periods

Time for repair or

rework of defective

work

7 Mishandling/error in Time for workers

construction

applications or

installations

resting on site and

other physiological

needs

8 Materials for rework or

repair of defective

work

9 Accidents on site

It is also imperative in this research to acknowledge some of the causes of

these waste on site so that a relationship between waste and cause is

established as a basis for thriving for continuous improvement. Five groups of

causal factors, that is, management & administration, people, execution,

material and information & communication factors have been recognized and

listed below.

1. Management and administration

Poor coordination among project participants

Poor planning and scheduling

Lack of control

Bureaucracy

2. People

Lack of trade skills

Inexperienced inspectors

Too few supervisors or foremen

Uncontrolled subcontracting practices

Poor labour distribution

Untimely supervision

3. Execution

Inappropriate construction methods

Outdated equipment

Equipment shortage

Ineffective equipment or poor choice of equipment

Poor site layout

Poor site documentation

4. materials

delay of material deliveries

poorly scheduled delivery of materials to site

poor quality material

misappropriation or misuse of material

poor storage of material

poor material handling on site

5. Information and communication

Defective or wrong information

Late information and decision making

Unclear information

3.2 Profile of respondents

This study is limited to site personnel. The respondents targeted include

foremen, site engineers and site based managers.

The foremen are the specific practitioners who are in direct contact with

labour, material and equipment and execute the construction. Site engineers

generally are the interface between the consultants and the construction

artisans. They interpret and explain the project to the foremen and artisans.

They are also involved in resource requisition and allocation. Site based

management will be involved in overall project execution, resource

management and coordination.

The profile of respondents may result in some research limitations of reliability

and validity, however care was taken to eliminate as much of the limitations

as possible (Saunders et al. 2007). The respondents work in the same

environment and fortunately for Grinaker-LTA, most of them have been with

the organization for a long time. The questionnaire will be structured in such a

way as to eliminate participant error, biases and observer errors. The study is

limited to two sites and may have limited validity, but due to the similarity of

operations within this particular business unit, the result will be a good

reflection of the real situation and be a good basis for future extensive studies

within the operating group. It is also assumed that there is a good chance of

generalizability of the result of the study.

3.3 Hypotheses

Descriptive analysis will be used to decipher the primary data once they are

collected. The descriptive analysis will be used to profile the respondents with

special emphasis being put on their work experience and exposure to the

Grinaker-LTA company culture. It is hoped that there is a correlation between

waste recognition and control with company culture that will emerge.

Analysis will be done separately for the three categories of waste so that

there is a better comparison of the conventional waste and new waste

categories under Lean Construction. The relationship between waste

recognition and deliberate attempt to control the waste will also be examined.

It is logical that recognition must lead to attempted control, but this may not

be so depending on company culture.

The hypotheses that will be tested in this study are:

Hypothesis 1: Direct conversion wastes are highly recognized and there is

an attempt to control them

Hypothesis 2: Non contributory time wastes are not easily recognized and

there is no attempt to control them

Hypothesis 3: Contributory time wastes are highly recognized but there is

no attempt to control them

3.4 Structure of the questionnaire

The questionnaire is divided into 4 sections. The first 2 sections of

questionnaire are intended to examine the general perception and

acceptance of Lean Construction philosophy based on the respondents’

waste recognition concepts. Respondents will asked to recognize 20 waste

elements and their personal experiences in controlling these waste elements

during construction processes. There are 2 options available for the

respondents and they will be required to answer whether the waste elements

listed is actually a waste or non-waste and whether they are controlled or not

controlled during the construction processes.

The third and fourth sections are intended to review the extent of waste

problems in the company by ranking them in terms of frequencies of

occurrences and rate the likelihood of particular waste sources and causes in

their construction practices where they work. For section 3, Respondents will

be able to identify how frequently the waste occurs using 5 categories: (1)

Never; (2) Very Rare; (3) Seldom; (4) Frequent; and (5) Very Frequent.

Respondents will be provided with five different scales from 1 (no significant

effect variable) to 5 as (high detrimental effect variable); In Section 4,

Respondents will be asked to determine the likelihood of particular waste

sources/ causes occurring using 4 categories: (1) Most unlikely; (2) Unlikely;

(3) Likely; (4) Most Likely and the respondents will be provided with five

different scales from 1 (no significant likelihood) to 5 (high likelihood).

3.5 Conclusion

Lean Construction models enable the categorization of waste and recognition

of the sources of waste. The conversion and flow model makes it possible to

track waste types along the construction process. The methodology applied in

this study is to first of all profile the respondents so that it may be possible to

correlate the findings to the profiles. Secondly, respondents will be asked to

recognize waste, say if it is mitigated on site and where they think the waste

emanates. Further more, three hypotheses have been put forward that will be

tested using descriptive analysis of the findings.

4.0 Data Analysis and Interpretation

4.1 Introduction

This chapter will give a presentation of the results from all returned

questionnaires as well as a discussion on the significance of the results. The

results will be tabulated showing the percentage rating of each variable.

Results from the tables will be drawn into graphs in order to give a visual view

of the results.

4.2 Response

A total of 42 questionnaires were sent out to personnel at Eastgate and

Samrand construction sites. There were 30 responses that were handed back

and used for this analysis. The response rate was 71% and the highest

number of responses came from Site Engineers as out of all the respondents

they represent 50%. Figure 4.1 below shows the classification of

respondents. It was hoped that Foremen would have had a higher response

so that the results of the study would not be biased towards the other groups.

Position held in GLTA

20%

20%50%

10%

Student

Foreman

Engineer

Manager

Figure 4.1. Response rate according to position within GLTA

Distribution of Experience in GLTA

30%

50%

10%

10%

0-2yr

2-5yr

5-10yr

10+yr

Figure 4.2. Respondent classification according to experience within

GLTA

Figure 4.2 above show the classification of respondents according to the

number of years that they have been in GLTA. 70% of the respondents have

been with the company for at least 2 years. This is a good enough time span

for the employees to have observed the practices within the company and

also form opinions about “how things are done around here”. Most importantly

there is 20% of respondents who have been within GLTA for more than 5

years.

4.3 General waste recognition

For the discussions on waste recognition, mitigation and frequency of

occurrence that are coming now a key of waste type and variables has been

done below that will identify waste as a colour code and variables as a

number.

Table 4.1 Key of waste type

Direct Conversation Waste    Contributory Waste      Non Contributory Waste    

Table 4.2 Key of Variables

Variable Description

1Waiting for others to complete their work before proceeding with other work

2 Waiting for equipment to be delivered to site3 Waiting for materials to be delivered to site4 Waiting for specialist subcontractors to come to site

5Waiting for clarification and confirmation from the client and consultants

6 Time for rework/repair of defective work7 Materials for rework/repair of defective work8 Time for workers resting on site during working periods9 Over-allocation/unnecessary equipment on site

10 Over-allocation/unnecessary material on site11 Over-allocation/unnecessary workers on site12 Unnecessary protocols on site13 Unclear lines of communication14 Materials stolen from site during construction15 Material deterioration on site16 Errors in construction applications17 Accidents on site18 Time for supervising and inspection of work

19Time for instructions and communication among different trades on the same job

20 Time for transporting workers, equipment and materials

Table 4.3 Matrix of results for general waste recognition

Variable WasteNon Waste

  % %1 80 202 90 103 100 04 80 205 100 06 100 07 90 108 80 209 100 0

10 90 1011 90 1012 90 1013 100 014 90 1015 100 016 100 017 100 018 30 7019 30 7020 20 80

Genaral Waste Recognition

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Variable

% R

eco

gn

itio

n

Waste

Non Waste

Figure 4.3 General waste recognition

There was a high rate of identification of direct conversion and non

contributory wastes. However there seemed to be an unawareness of

contributory waste. This may be attributed to the traditional thinking of waste

in construction. The Conversion-Flow Model recognizes contributory time as a

waste that must also be minimized. There was a tolerance towards waiting

and break times for workers. A lot of respondents identified this as non-waste.

The mean recognition of waste was 83% which indicates that personnel on

site are highly aware of waste.

4.4 Waste Mitigation Scenario

Table 4.4 Matrix of results for mitigation of waste

Variable Yes No  % %

1 50 502 50 503 70 304 60 405 70 306 70 307 80 208 70 309 50 50

10 40 6011 40 60

12 60 4013 30 7014 70 3015 50 5016 50 5017 40 6018 60 4019 60 4020 50 50

Mitigation Scenario

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Variable

% M

itig

atio

n

Mitigation

No Mitigation

Figure 4.4 Waste mitigation scenario

The mean mitigation rate is 56% and non-mitigation is 44%. Contributory and non

contributory have a higher margin with mean mitigation rate of 56% and 65%

respectively. Direct conversion wastes have problems with a mean mitigation rate of

48%. The overall picture however is inconclusive because the results show that

although personnel can recognize waste, it does not necessarily mean that they

mitigate these wastes.

4.5 Frequency of Occurrence

Table 5.5 Matrix of frequencies of waste occurrences

Variable 1 2 3 4 5  % % % % %

1 0 0 20 60 202 0 10 40 30 203 10 0 40 30 204 0 20 40 30 105 0 10 30 40 206 0 20 10 30 307 0 10 40 20 308 20 10 40 10 209 0 20 40 30 10

10 10 20 30 30 1011 20 10 40 20 2012 10 30 30 20 1013 10 0 20 40 3014 0 10 20 50 2015 10 30 20 30 1016 10 10 40 20 2017 0 30 30 30 1018 0 0 30 30 4019 0 0 40 20 4020 0 0 50 10 40

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

never

very rare

seldom

frequently

very frequently

Figure 4.5 Frequency of occurrence of wastesThe mean frequencies are; never (6%), very rare (12%), seldom (32%), frequently

(29%) and very frequently (21%). The frequency of occurrence that is between

wastes occurring frequently and very frequently is 50%. This shows that half the time

when any operation is taking place on site there is wastage.

4.6 Sources and Causes of Waste

In the table below, the figures in red are the mean values of each selected rating options.

Table 4.6 Sources and causes of waste

` Description      Most

unlikely unlikely likelyMost likely

          % % % %

1

Management and Administration       0 30 55 15

 Poor coordination among project participants 0 10 80 10

  Poor planning and scheduling 0 40 20 40

  Lack of control 0 30 60 10  Bureaucracy 0 40 60 02 People 4 20 50 26  Lack of trade skills 0 10 40 50  Inexperienced inspectors 20 10 30 40  Too few supervisors 0 40 50 10  Uncontrolled subcontracting practices 0 30 50 20  Poor labour distribution 0 10 80 103 Execution 4 40 42 14  Inappropriate construction methods 0 20 70 10  Outdated equipment 0 30 50 20  Lack of equipment 0 40 40 20  Poor site layout 10 60 20 10  Poor site documentation 10 50 30 104 Material 10 14 44 34

 Poor schedule of delivery of material to site 10 20 40 30

  Late delivery of materials to site 0 20 50 30  Misuse of materials 0 10 60 30  Poor storage of materials 20 10 50 30  Poor handling of materials 20 10 20 505 Information and Communication 0 13 23 63  Wrong information 0 30 30 40  Late information 0 0 20 80  Unclear information 0 10 20 70

The results in Table 4.6 above show that all the 5 variables are likely or most

likely sources of waste. In all cases, the mean of the variable being a cause of

waste is above 50%. Poor planning (40%), lack of trade skills (50%), poor

handling of materials (50%), late information (80%) and unclear information

(70%) stand out as the problem areas that most likely cause waste on site

4.6 Discussion of findings

The findings of this study in many respects concur with literature that has

been discussed in Chapter 2. The derivative equation from the conversion

flow model suggests that the cycle time of a process involves conversion,

handling, inspection and waiting. That is

Cycle time = processing + handling + inspection + waiting

On the aspect of waste recognition, it is clear that site staff identified

processing, handling and waiting wastes but failed in most instances to

recognize inspection as a waste. The equation above recognizes inspection

as a consumer of time that must be minimized in as much as it is necessary.

The other categories of waste were easily identified because they could be

easily turned into monetary value.

As surprising as it is to difficult to understand, recognition of waste does not

necessarily lead to its mitigation. It was easy to recognize direct conversion

waste but no proportional effort was spent in mitigation. From literature it was

acknowledged that one of the endemic problems in construction is waste that

has become acceptable over time that it is actually factored when tendering

for work. This thinking may be so deep-rooted that site staff does not see the

negative consequence of wastage in processing activities. Contributory and

non-contributory wastes were viewed as avoidable wastes because they do

not take a lot of money to rectify. This view is supported by Serpell’s

classification of waste as avoidable or unavoidable waste.

The findings also point to the fact that all sources of waste as suggested in

the Lean Construction theory are in fact causes of waste in GLTA. All five

sources had scores of higher than 50% likelihood of being a cause of waste

on site.

According to Shingo and the Institute of Lean Thinking, these findings imply

directly that GLTA is not lean and that it is losing profitability and the

competitive edge by not making its operations efficient.

5.0 Conclusions and Recommendations

5.1 Introduction

This chapter concludes the study by discussing the results in relation to the

objectives of the study and the hypotheses postulated. Recommendations will

also be suggested on improvements that can be made based on the problem

areas and positives found in the study.

5.2 Relating research findings to research objectives

5.2.1 Objective 1: To examine the general perception and attitude

towards and practice of lean construction principles within Grinaker-

LTA.

From the research results, it was discovered that there was a high incidence

of recognition of direct conversion and non-contributory waste and a dismally

low recognition of contributory waste. The underlying reasons for this may be

that personnel can easily quantify waste or loss due to conversion processes

and non contributory time into monetary value. For instance, it is easy to

quantify how much loss one makes by paying an employee for an hour for no

work done or throwing away material. Contributory waste is regarded as

acceptable because traditionally without the professional teams’ approval of

work, no further work may be carried out. What must be realised according to

the Lean thinking process is that although contributory waste may be

necessary, it is still a waste that must be minimized. If there is minimization,

then the cycle time is reduced which results in less waste. As surprising as it

is unfathomable, the tendency to mitigate the recognized waste is not as

great. There is need to study why personnel do not have an attitude that

wants to eliminate waste. My suspicions are that this problem may be deep

rooted in the GLTA culture or there is little encouragement and support to

achieve no waste on sites. In conclusion, it seems that there is some

appreciation of Lean Construction principles within the site personnel albeit

unscientific. GLTA is neither traditionalistic nor modernistic in approach and

there is need to formalize the principles of lean construction in order to

achieve less wastage and more profit.

5.2.2 Objective 2: Examine the extent of problems arising from waste

identified in the current scenario

The scenario that close to 90% of waste is identified on site and only 56% is

actively mitigated paints a grim picture of an organization that is trying to

move forward in terms of operational efficiency. The study shows that

personnel are able to see what is going wrong on site and for some reasons

they do not take action to mitigate the wrongs. The extent of the problems is

that on any activity that is happening on site, half the time there is wastage

taking place and nobody bothers to eliminate the waste or its causes.

5.2.3 Objective 3: Identify the sources of waste

In the study, there were 5 areas identified by lean thinking as possible

sources and causes of waste that were tested. It clearly came out that all the

5 sources, namely management and administration, people, execution,

material and communication and information are all sources and causes of

waste. Each of these areas had a mean score above 50% for the likelihood

that it was a source of waste. GLTA needs to do an introspection of the whole

organization to see where improvements can be made. This in no way means

that the company is not successful, but simply points to the fact that the

organization is not realizing its full potential. In conclusion, the study identified

the sources and causes of waste in GLTA.

5.2.4 Objective 4: Study the possible improvements aimed at eliminating

waste

Although no direct questions were paused suggesting areas of improvement,

the study shows all the areas that cause or are a source of waste. These are

the areas that need attention and should be worked on. In the next

discussions possible improvements will be suggested on how to eliminate

waste. The study there fore, was successful in identifying waste and its

sources. This information will be utilized in formulating interventions aimed at

reducing and eliminating waste

5.3 Relating research study to hypotheses

The hypotheses suggested in Chapter 4 will be re-written in view of the facts

gathered from the study as follows:

Hypothesis 1: Direct conversion wastes are highly recognized and there is

a significant attempt to control them.

Hypothesis 2: Non contributory time wastes are easily recognized and

there is no significant attempt to control them.

Hypothesis 3: Contributory time wastes are not easily recognized and

there is no significant attempt to control them.

The fact that only direct conversion wastes have a significant attempt at being

controlled shows a traditional mindset of waste control. Recognizing waste does not

prompt action to control the waste. There could be a lot of factor for this fact. It could

be that personnel are not empowered to take action, the cost of taking action may be

higher than letting waste occur or utter ignorance of the principles of waste control.

This defies logic; however it is a fact that was discovered in the research study.

However, without any deliberate scientific interventions, it will be impossible to

really measure the attitude of personnel on waste management. There fore further

studies need to be done in educating personnel about waste and waste control. This

will be the basis where GLTA can start to learn about itself and improving itself.

5.3 Recommendations

The process of implementing lean construction methods to identifying and

reducing waste involves a change of mindset and sometimes organizational

culture. The overall goal is to achieve construction process optimization and

efficiency in sub-activities by embracing the attitude of waste identification

and elimination. As such, it is a challenge to introduce lean thinking into an

organization. For GLTA, the challenges are similar but this section will look at

ways that the organization can take itself forward and start performing at

world class levels. The reality of the situation is that with globalization and

increased competition from foreign companies, only lean companies will

survive. The following are some of the fundamental recommendations that

GLTA can make on the road to Lean Construction:

Management commitment

Management must provide leadership for the new philosophy. They must

understand the philosophy of Lean Construction and be able to preach it to

their subordinates. There will always be resistance to change especially new

endeavours that may be met with a lot of scepticism from employees that

have been in the organization for along time. Management commitment will

be required for that change to occur. Management must take time to

communicate and filter the new ideology to employees. Road shows may be

conducted on sites and must include junior and senior staff.

Benchmarking

Successes in Lean Construction must be measurable. Initially the

organization needs to understand itself through a process of Value Stream

Mapping. Deliberate interventions must be identified in the system and goals

set for improvement. The focus should be on actionable and measurable

improvement rather than on developing abstract capabilities. Successes must

be quantified and celebrated as these short term successes create motivation

and reinforcement to further successes. Steadily GLTA will create its on

benchmarks for lean construction which may be compared to external

benchmarks for further improvement or maintaining industry leadership.

Employee Involvement

Employees are motivated when they are made to be part of the solution.

Hierarchies in the organization do not need to change, but whenever there is

an intervention needed, employees must be made part of the solution seeking

team. This may be done in focus groups that brainstorm solutions. Feedback

must be given back so that they appreciate their involvement. Such solutions

are likely to be accepted and implemented without too much resistance.

Employees must also be given the powers to make major decisions as long

as they fall within the company guidelines. Planning for the job must also

involve foremen and engineers on site so that they take ownership of the

plan, rather than have it forced down their throat.

Learning

Implementation requires a substantial amount of learning. Initial learning for

employees who are already in the company would involve teaching them the

principles and tools of lean construction and the rewards that come with the

new philosophy. On the job reinforcement will be required to make the

process of adaptation work. For new employees, there must be a process of

orientation that will reinforce the requirements of GLTA. This will ensure a

workforce that is cohesive. A learning organization is a winning organization.

After every project there must be a debriefing process that captures mistakes

and successes and these would be put in the company knowledge vault for

future use.

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Appendix

1. Questionnaire

INTRODUCTION

This questionnaire is part of a study to find the extent to which GLTA Building Inland sites have waste problems and create a road map to reducing the waste. The questionnaire is divided into 4 sectionsthat will need to be filled in as accurately as possible depending on your experiences, perception oropinion

I would you to thank you for taking part in this study and would like to assure you that your responseswill be treated with the utmost confidence

PROFILE

How many years have you been with the company

0-2 years     2-5 years        5-10 years        over 10 years  

What position do you hold on site

Student     Foremen     Engineer/QS     Management     

1 General Waste IdentificationIndicate in the following Table items that according to your opinion and understanding are "waste" or

"non-waste". Please indicate with X

item Description wastenon-waste

1 Waiting for others to complete their work before proceeding with other work    

2 Waiting for equipment to be delivered to site    

3 Waiting for materials to be delivered to site    

4 Waiting for specialist subcontractors to come to site    

5 Waiting for clarification and confirmation from the client and consultants    

6 Over-allocation/unnecessary equipment on site    

7 Over-allocation/unnecessary material on site    

8 Over-allocation/unnecessary workers on site    

9 unnecessary protocols on site    

10 Unclear lines of communication    

11 Materials stolen from site during construction    

12 Material deterioration on site    

13 Errors in construction applications    

14 Time for rework/repair of defective work    

15 Materials for rework/repair of defective work    

16 Time for workers resting on site during working periods    

17 Time for supervising and inspection of work    

18 Time for instructions and communication among different trades on the same job    

19 Time for transporting workers, equipment and materials    

20 Accidents on site    

2 Existing ScenarioAccording to your experience in the construction within Grinaker-LTA, are the following items properly

controlled or mitigated wherever they occur. Please indicate with X whether you agree or disagree

item Description Yes No

1 Waiting for others to complete their work before proceeding with other work    

2 Waiting for equipment to be delivered to site    

3 Waiting for materials to be delivered to site    

4 Waiting for specialist subcontractors to come to site    

5 Waiting for clarification and confirmation from the client and consultants    

6 Over-allocation/unnecessary equipment on site    

7 Over-allocation/unnecessary material on site    

8 Over-allocation/unnecessary workers on site    

9 Unnecessary protocols on site    

10 Unclear lines of communication    

11 Materials stolen from site during construction    

12 Material deterioration on site    

13 Errors in construction applications    

14 Time for rework/repair of defective work    

15 Materials for rework/repair of defective work    

16 Time for workers resting on site during working periods    

17 Time for supervising and inspection of work    

18Time for instructions and communication between different trades on the same job    

19 Time for transporting workers, equipment and materials    

20 Accidents on site    

3 Frequency of Occurrence

According to your experience in GLTA, what is the prevalence of occurrence of the following items. The response must be between never and vey

frequently. Please indicate with X in the appropriate box

item Description NeverVery rare

1 Waiting for others to complete their work before proceeding with other work    

2 Waiting for equipment to be delivered to site    

3 Waiting for materials to be delivered to site    

4 Waiting for specialist subcontractors to come to site    

5 Waiting for clarification and confirmation from the client and consultants    

6 Over-allocation/unnecessary equipment on site    

7 Over-allocation/unnecessary material on site    

8 Over-allocation/unnecessary workers on site    

9 Unnecessary protocols on site    

10 Unclear lines of communication    

11 Materials stolen from site during construction    

12 Material deterioration on site    

13 Errors in construction applications    

14 Time for rework/repair of defective work    

15 Materials for rework/repair of defective work    

16 Time for workers resting on site during working periods    

17 Time for supervising and inspection of work    

18Time for instructions and communication among different trades on the same job    

19 Time for transporting workers, equipment and materials    

20 Accidents on site    

4 Sources and Causes of Waste

In your opinion and experience in GLTA, rate the items shown in the following Table as the cuases or sources of waste on site. You may rate the items as most unlikely up to most likely. Indicate with X the appropriate rating

item Descriptionmost

unlikely unlikely

1 Management and Administration    

  Poor coordination among project participants    

  Poor planning and scheduling    

  Lack of control    

  Bureaucracy    

2 People    

  Lack of trade skills    

  Inexperienced inspectors    

  Too few supervisors    

  Uncontrolled subcontracting practices    

  Poor labour distribution    

3 Execution    

  Inappropriate construction methods    

  Outdated equipment    

  Lack of equipment    

  Poor site layout    

  Poor site documentation    

   most unlikely unlikely

4 Material    

  Poor schedule of delivery of materil to site    

  Late delivery of materials to site    

  Misuse of materials    

  Poor storage of materials    

  Poor handling of materials    

5 Information and Communication    

  Wrong information    

  Late information    

  Unclear information