FMEA analysis

Effectiveness of Lean Manufacturing at Sri Chakra TVS

EFFECTIVENESS OF LEAN MANUFACTURING IN SRICHAKRA TVS TYRES

1.1 Introduction to Lean Manufacturing

Lean manufacturing, lean enterprise, or lean production, often simply, "Lean," is a production

practice that considers the expenditure of resources for any goal other than the creation of value for

the end customer to be wasteful, and thus a target for elimination. Working from the perspective of

the customer who consumes a product or service, "value" is defined as any action or process that a

customer would be willing to pay for. Basically - using techniques to cut down waste in a business

thereby improving efficiency.

The benefits generally are lower costs, higher quality, and shorter lead times. The term "lean

manufacturing" is coined to represent half the human effort in the company, half the manufacturing

space, half the investment in tools, and half the engineering hours to develop a new product in half

the time.

The characteristics of lean processes are:

Single-piece production

Repetitive order characteristics

Just-In-Time materials/pull scheduling

Short cycle times

Quick changeover

Continuous flow work cells

Collocated machines, equipment, tools and people

Compressed space

Multi-skilled employees

Flexible workforce

Empowered employees

Acharya Institute of Management & Sciences Page 1

http://en.wikipedia.org/wiki/Value_(economics)


Types of Wastes

The elimination of waste is the goal of Lean, and Toyota defines the original seven types of wastes

(MUDA). They are

Transport (moving products that are not actually required to perform the processing)

Inventory (all components, work in process and finished product not being processed)

Motion (people or equipment moving or walking more than is required to perform the

processing)

Waiting (waiting for the next production step)

Overproduction (production ahead of demand)

Over Processing (resulting from poor tool or product design creating activity)

Defects (the effort involved in inspecting for and fixing defects)

1.2 Lean Goals & Strategy

The espoused goals of Lean manufacturing systems differ between various authors. While some

maintain an internal focus, e.g. to increase profit for the organization others claim that

improvements should be done for the sake of the customer

Some commonly mentioned goals are:

Improve quality: To stay competitive in today's marketplace, a company must understand its

customers' wants and needs and design processes to meet their expectations and requirements.

Eliminate waste: Waste is any activity that consumes time, resources, or space but does not add

any value to the product or service.

Reduce time: Reducing the time it takes to finish an activity from start to finish is one of the

most effective ways to eliminate waste and lower costs.

Reduce total costs: To minimize cost, a company must produce only to customer demand.

Overproduction increases a company’s inventory costs because of storage needs.

The strategic elements of Lean can be quite complex, and comprise multiple elements. Four

different notions of Lean have been identified


http://en.wikipedia.org/wiki/Work_in_process


Lean as a fixed state or goal (Being Lean)

Lean as a continuous change process (Becoming Lean)

Lean as a set of tools or methods (Doing Lean/Toolbox Lean)

Lean as a philosophy (Lean thinking)

1.3 Concepts to Achieve Lean

The five-step thought process for guiding the implementation of lean techniques is easy to

remember, but not always easy to achieve:

Specify value from the standpoint of the end customer by product family.

Identify all the steps in the value stream for each product family, eliminating whenever

possible those steps that do not create value.

Make the value-creating steps occur in tight sequence so the product will flow smoothly

toward the customer.

As flow is introduced, let customers pull value from the next upstream activity.

As value is specified, value streams are identified, wasted steps are removed, and flow and

pull are introduced, begin the process again and continue it until a state of perfection is

reached in which perfect value is created with no waste.

Fig 1.1



1.4 Benefits of Lean Manufacturing

Lean Manufacturing is a business improvement philosophy that has developed over many years, it

is a method to better focus your business on the true needs of the customer to help you prevent

waste from being built into your system. The benefits of Lean manufacturing are many;

Improved Customer Service; delivering exactly what the customer wants when they want it.

Improved Productivity; Improvements in throughput and value add per person.

Quality; Reductions in defects and rework.

Innovation; staff are fully involved so improved morale and participation in the business

Reduced Waste; Less transport, moving, waiting, space, and physical waste.

Improved Lead Times; Business able to respond quicker, quicker set ups, fewer delays.

Improved Stock Turns; Less work in progress and Inventory, so less capital tied up.

All of the above have financial impacts on your business, as well as helping you become a business

that can better react to and meet your customer's needs.

In addition to this lean will reduce your internal costs, your processes will be more efficient, less

wasteful. You will have less of your businesses cash tied up in wasteful inventory and work in

progress enabling you to spend it where you want.



Lean will improve your staffs morale as they become more and more involved in your business and

improving what you do, their motivation will improve dramatically.

1.5 Failure Mode & Effect Analysis

A Failure Modes and Effects Analysis (FMEA) is a procedure in product development, systems

engineering and operations management for analysis of potential failure modes within a system for

classification by the severity and likelihood of the failures. A successful FMEA activity helps a

team to identify potential failure modes based on past experience with similar products or

processes, enabling the team to design those failures out of the system with the minimum of effort

and resource expenditure, thereby reducing development time and costs. Because it forces a review

of functions and functional requirements, it also serves as a form of design review. It is widely used

in manufacturing industries in various phases of the product life cycle and is now increasingly

finding use in the service industry. Failure modes are any errors or defects in a process, design, or

item, especially those that affect the intended function of the product and or process, and can be

potential or actual. Effects analysis refers to studying the consequences of those failures.

In general, Failure Modes, Effects and Criticality Analysis (FMEA / FMECA) requires the

identification of the following basic information:

Item(s)

Function(s)

Failure(s)

Effect(s) of Failure

Cause(s) of Failure

Current Control(s)

Recommended Action(s)

Plus other relevant details

Most analyses of this type also include some method to assess the risk associated with the issues

identified during the analysis and to prioritize corrective actions. Two common methods include:

Risk Priority Numbers (RPNs)

Criticality Analysis (FMEA with Criticality Analysis = FMECA)


http://en.wikipedia.org/wiki/Design_review

http://en.wikipedia.org/wiki/Systems_engineering



1.5.1 Basic Terms

Failure

The loss of an intended function of a device under stated conditions.

Failure Mode

The manner by which a failure is observed; it generally describes the way the failure

occurs.

Failure Effect

Immediate consequences of a failure on operation, function or functionality, or status of

some item

Indenture Levels

An identifier for item complexity. Complexity increases as levels are closer to one.

Local Effect

The failure effect as it applies to the item under analysis.

Next Higher Level Effect

The failure effect as it applies at the next higher indenture level.

End Effect

The failure effect at the highest indenture level or total system.

Failure Cause

Defects in design, process, quality, or part application, which are the underlying cause of

the failure or that initiate a process that leads to failure.

Severity

The consequences of a failure mode. Severity considers the worst potential consequence of

a failure, determined by the degree of injury, property damage, or system damage that could

ultimately occur.

Fig 1.2



1.5.2 Pre Work

The process for conducting an FMEA is typically developed in three main phases, in which

appropriate actions need to be defined. Before starting with an FMEA, several other techniques are

frequently employed to ensure that robustness and history are included in the analysis.

A robustness analysis can be obtained from interface matrices, boundary diagrams, and parameter

diagrams. Failures are often found from external 'noise factors' and from shared interfaces with

other parts and/or systems.

Typically, a description of the system and its function is developed, considering both intentional

and unintentional uses.

A block diagram of the system is often created for inclusion with the FMEA, giving an overview of

the major components or process steps and how they are related. These are called logical relations

around which the FMEA can be developed.

The primary FME document or 'worksheet' lists all of the items or functions of the system in a

logical manner, typically based on the block diagram.


http://en.wikipedia.org/w/index.php?title=Parameter_diagrams&action=edit&redlink=1



1.5.3 Sample Worksheet

Example FMEA Worksheet

Item /

Function

Potential

Failure

mode

Potential

Effects

of

Failure

S

(severity

rating)

Potential

Cause(s)

O

(occurrence

rating)

Current

controls

D

(detection

rating)

CRIT

(critical

characteristic

RPN

(risk

priority

number)

Recommended

actions

Responsibility

and target

completion

date

Action

taken

New

S

New

O

New

D

New

RPN

Fill tub High level

sensor is

disconnected

Liquid

spills on

customer

floor

8 sensor is

exposed at

top and can

be easily

disconnected

by user

2 Fill

timeout

based on

time to

fill to

low

level

sense

5 N 80 Perform cost

analysis of

adding

additional

sensor halfway

between low

and high level

sensors to

calculate fill

rate at mid-

Jane Doe

15-May-2012



point and

determine max

fill volume in

case high level

sensor is

disconnected

1.6 Basic Analysis Procedure for FMEA Or FMECA

The basic steps for performing an Failure Mode and Effects Analysis (FMEA) or Failure Modes,

Effects and Criticality Analysis (FMECA) include

Assemble the team.

Establish the ground rules.

Gather and review relevant information.

Identify the item(s) or process(es) to be analyzed.

Identify the function(s), failure(s), effect(s), cause(s) and control(s) for each item or process

to be analyzed.

Evaluate the risk associated with the issues identified by the analysis.

Prioritize and assign corrective actions.

Perform corrective actions and re-evaluate risk.

Distribute, review and update the analysis, as appropriate.

1.7 Risk Evaluation Methods

A typical failure modes and effects analysis incorporates some method to evaluate the risk

associated with the potential problems identified through the analysis. The two most common

methods, Risk Priority Numbers and Criticality Analysis, are described next.

Risk Priority Numbers

To use the Risk Priority Number (RPN) method to assess risk, the analysis team must:

Rate the severity of each effect of failure.



Rate the likelihood of occurrence for each cause of failure.

Rate the likelihood of prior detection for each cause of failure (i.e. the likelihood of

detecting the problem before it reaches the end user or customer).

Calculate the RPN by obtaining the product of the three ratings:

RPN = Severity x Occurrence x Detection

The RPN can then be used to compare issues within the analysis and to prioritize problems for

corrective action. This risk assessment method is commonly associated with Failure Mode and

Effects Analysis (FMEA).

Criticality Analysis

The MIL-STD-1629A document describes two types of criticality analysis: quantitative and

qualitative. To use the quantitative criticality analysis method, the analysis team must:

Define the reliability/unreliability for each item and use it to estimate the expected number

of failures at a given operating time.

Identify the portion of the item’s unreliability that can be attributed to each potential failure

mode.

Rate the probability of loss (or severity) that will result from each failure mode that may

occur.

Calculate the criticality for each potential failure mode by obtaining the product of the three

factors:

Mode Criticality = Expected Failures x Mode Ratio of Unreliability x Probability of Loss

Calculate the criticality for each item by obtaining the sum of the criticalities for each

failure mode that has been identified for the item.

Item Criticality = SUM of Mode Criticalities

To use the qualitative criticality analysis method to evaluate risk and prioritize corrective actions,

the analysis team must:

Rate the severity of the potential effects of failure.

Rate the likelihood of occurrence for each potential failure mode.

Compare failure modes via a Criticality Matrix, which identifies severity on the horizontal

axis and occurrence on the vertical axis.



These risk assessment methods are commonly associated with Failure Modes, Effects and

Criticality Analysis (FMECA).

CHAPTER 2

REVIEW OF LITERATURE & RESEARCH DESIGN

2.1 Introduction

Lean manufacturing, lean enterprise, or lean production, often simply, "Lean," is a production

practice that considers the expenditure of resources for any goal other than the creation of value for

the end customer to be wasteful, and thus a target for elimination. Working from the perspective of

the customer who consumes a product or service, "value" is defined as any action or process that a

customer would be willing to pay for. basically - using techniques to cut down waste in a business

thereby improving efficiency .

Essentially, lean is centered on preserving value with less work. Lean manufacturing is a

management philosophy derived mostly from the Toyota Production System (TPS) (hence the term

Toyotism is also prevalent) and identified as "Lean" only in the 1990.TPS is renowned for its focus

on reduction of the original Toyota seven wastes to improve overall customer value, but there are

varying perspectives on how this is best achieved. The steady growth of Toyota, from a small



company to the world's largest automaker has focused attention on how it has achieved this. Lean

manufacturing is a variation on the theme of efficiency based on optimizing flow.

Lean Manufacturing is an operational strategy oriented toward achieving the shortest possible cycle

time by eliminating waste. It is derived from the Toyota Production System and its key thrust is to

increase the value-added work by eliminating waste and reducing incidental work. The technique

often decreases the time between a customer order and shipment, and it is designed to radically

improve profitability, customer satisfaction, throughput time, and employee morale.

2.1.1 Origin of Lean:

Lean principles come from the Japanese manufacturing industry. The term was first coined by John

Krafcik in a Fall 1988 article, "Triumph of the Lean Production System," published in the Sloan

Management Review and based on his master's thesis at the MIT Sloan School of Management. ]Krafcik had been a quality engineer in the Toyota-GM NUMMI joint venture in California before

coming to MIT for MBA studies. Krafcik's research was continued by the International Motor

Vehicle Program (IMVP) at MIT, which produced the international best-seller book co-authored by

Jim Womack, Daniel Jones, and Daniel Roos called The Machine That Changed the World. A

complete historical account of the IMVP and how the term "lean" was coined is given by Holweg

(2007).

For many, Lean is the set of "tools" that assist in the identification and steady elimination of waste

(muda). As waste is eliminated quality improves while production time and cost are reduced.

Examples of such "tools" are Value Stream Mapping, Five S, Kanban (pull systems), and poka-

yoke (error-proofing).

There is a second approach to Lean Manufacturing, which is promoted by Toyota, in which the

focus is upon improving the "flow" or smoothness of work, thereby steadily

eliminating mura ("unevenness") through the system and not upon 'waste reduction' per se.

Techniques to improve flow include production leveling, "pull" production (by means of kanban)

and the Heijunka box . This is a fundamentally different approach from most improvement

methodologies, which may partially account for its lack of popularity.

The difference between these two approaches is not the goal itself, but rather the prime approach to

achieving it. The implementation of smooth flow exposes quality problems that already existed, and

thus waste reduction naturally happens as a consequence. The advantage claimed for this approach

is that it naturally takes a system-wide perspective, whereas a waste focus sometimes wrongly

assumes this perspective.


http://en.wikipedia.org/wiki/Heijunka_box

http://en.wikipedia.org/wiki/Kanban

http://en.wikipedia.org/wiki/Production_leveling

http://en.wikipedia.org/wiki/Mura_(Japanese_term)

http://en.wikipedia.org/wiki/Poka-yoke

http://en.wikipedia.org/wiki/Poka-yoke

http://en.wikipedia.org/wiki/Kanban

http://en.wikipedia.org/wiki/Muda_(Japanese_term)

http://en.wikipedia.org/wiki/International_Motor_Vehicle_Program

http://en.wikipedia.org/wiki/International_Motor_Vehicle_Program


Both Lean and TPS can be seen as a loosely connected set of potentially competing principles

whose goal is cost reduction by the elimination of waste.[5] These principles include: Pull

processing, Perfect first-time quality, Waste minimization, Continuous improvement, Flexibility,

Building and maintaining a long term relationship with suppliers, Autonomation, Load leveling and

Production flow and Visual control. The disconnected nature of some of these principles perhaps

springs from the fact that the TPS has grown pragmatically since 1948 as it responded to the

problems it saw within its own production facilities. Thus what one sees today is the result of a

'need' driven learning to improve where each step has built on previous ideas and not something

based upon a theoretical framework.

Toyota's view is that the main method of Lean is not the tools, but the reduction of three types of

waste: muda ("non-value-adding work"), muri ("overburden"), and mura ("unevenness"), to expose

problems systematically and to use the tools where the ideal cannot be achieved. From this

perspective, the tools are workarounds adapted to different situations, which explains any apparent

incoherence of the principles above.

Also known as the flexible mass production, the TPS has two pillar concepts: Just-in-time (JIT) or

"flow", and "autonomation" (smart automation). Adherents of the Toyota approach would say that

the smooth flowing delivery of value achieves all the other improvements as side-effects. If

production flows perfectly then there is no inventory; if customer valued features are the only ones

produced, then product design is simplified and effort is only expended on features the customer

values. The other of the two TPS pillars is the very human aspect of autonomation, whereby

automation is achieved with a human touch. The "human touch" here meaning to automate so that

the machines/systems are designed to aid humans in focusing on what the humans do best. This

aims, for example, to give the machines enough intelligence to recognize when they are working

abnormally and flag this for human attention. Thus, in this case, humans would not have to monitor

normal production and only have to focus on abnormal, or fault, conditions.

Lean implementation is therefore focused on getting the right things to the right place at the right

time in the right quantity to achieve perfect work flow, while minimizing waste and being flexible

and able to change. These concepts of flexibility and change are principally required to allow

production leveling, using tools like SMED, but have their analogues in other processes such

as research and development (R&D). The flexibility and ability to change are within bounds and not

open-ended, and therefore often not expensive capability requirements. More importantly, all of

these concepts have to be understood, appreciated, and embraced by the actual employees who

build the products and therefore own the processes that deliver the value. The cultural and

managerial aspects of Lean are possibly more important than the actual tools or methodologies of


http://en.wikipedia.org/wiki/Research_and_development

http://en.wikipedia.org/wiki/SMED

http://en.wikipedia.org/wiki/Autonomation

http://en.wikipedia.org/wiki/Just-in-time_(business)

http://en.wikipedia.org/wiki/Workaround

http://en.wikipedia.org/wiki/Mura_(Japanese_term)

http://en.wikipedia.org/wiki/Muri_(Japanese_term)

http://en.wikipedia.org/wiki/Muda_(Japanese_term)

http://en.wikipedia.org/wiki/Autonomation

http://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-4


production itself. There are many examples of Lean tool implementation without sustained benefit,

and these are often blamed on weak understanding of Lean throughout the whole organization.

Lean aims to make the work simple enough to understand, do and manage. To achieve these three

goals at once there is a belief held by some that Toyota's mentoring process,(loosely

called Senpai and Kohai, which is Japanese for senior and junior), is one of the best ways to foster

Lean Thinking up and down the organizational structure. This is the process undertaken by Toyota

as it helps its suppliers improve their own production. The closest equivalent to Toyota's mentoring

process is the concept of "Lean Sensei," which encourages companies, organizations, and teams to

seek outside, third-party experts, who can provide unbiased advice and coaching, (see Womack et

al., Lean Thinking, 1998).

There have been recent attempts to link Lean to Service Management, perhaps one of the most

recent and spectacular of which was London Heathrow Airport's Terminal. This particular case

provides a graphic example of how care should be taken in translating successful practices from one

context (production) to another (services), expecting the same results. In this case the public

perception is more of a spectacular failure, than a spectacular success, resulting in potentially an

unfair tainting of the lean manufacturing philosophies.

2.2 Review Of Literature

On January 30th 1997, a study was conducted by Auston Marmaduke Kilpatrick from the

department of B.S. Mechanical Engineering, University of California, Los Angeles on the title of

Lean Manufacturing Principles: A Comprehensive Framework for Improving Production

Efficiency.

His major findings were on the factors which contribute to Internal Defect Costs, External Defect

Costs, Escapes, Backlog of ordered units, Changeover time and on time delivery percentage

His conclusion was that we now define Tall as the length of time the customer is willing to wait for

product after having paid for the order. We will call Tall the allowable lead time for post payment

production. For some products this may be close to zero. However, for many products, such as

prepared food, cars, and all items that are sold through catalogues, Tall ranges from a few weeks to

two years. For most products, the order lead time (OLT) using traditional manufacturing methods is

much longer than Tall. As long as the OLT is longer than Tall, it is necessary for factories and sales


http://en.wikipedia.org/w/index.php?title=Lean_Sensei&action=edit&redlink=1

http://en.wikipedia.org/wiki/Kohai

http://en.wikipedia.org/wiki/Senpai


rooms to carry an inventory of finished goods which the customer can obtain product within Tall.

The factory must then produce to fill this inventory.

On July 2009, a Study was conducted on Lean Manufacturing Implementation in the Malaysian

Electrical and Electronics Industry by Yu Cheng Wong from the Department of Manufacturing

and Industrial Engineering.

His major findings were on the descriptive statistics for the respondent companies in terms of their

sizes, types of industry and the number of years for which they have adopted lean manufacturing. It

can be seen that only 31.82% were from Small and Medium Enterprises (SMEs) while the

remainder was large organizations. The classification of companies’ size was based on the

definition provided by the Malaysian National SME Development Council (2005). In this research,

large companies are those that have more than 150 employees in total. Apparently, there are more

large organizations than SMEs which have implemented lean manufacturing.

He concluded that the companies are found to have a good Understanding of lean manufacturing,

and since its implementation, they have gained many benefits such as reduced cost and improved

productivity. It is also apparent that the companies have Implemented various tools and techniques

to support lean manufacturing, and they do not adopt a single tool in isolation. In order to assess the

extent to which they have implemented lean.

On August 2007, Jostein Pettersen a student at the Division of Quality Technology and

Management & Helix VINN Excellence Centre Linköping University, Sweden, has conducted a

study on Defining Lean Production: Some conceptual and practical issues.

He founded that in the paper that there is no consensus on a definition of Lean Production between

the examined authors. The authors also seem to have different opinions on which characteristics

that should be associated with the concept. Overall it can be concluded that Lean Production is not

clearly defined in the reviewed literature. This divergence can cause some confusion on a

theoretical level, but is probably more problematic on a practical level when organizations aim to

implement the concept. This paper argues that it is important for an organization to acknowledge

the different variations, and to raise the awareness of the input in the implementation process. It is

further argued that the organization should not accept any random variant of Lean, but make active

choices and adapt the concept to suit the organization’s needs. Through this process of adaptation,



the organization will be able to increase the odds of performing a predictable and successful

implementation.

He concluded that There is no agreed upon definition of Lean that could be found in the reviewed

literature, and the formulations of the overall purpose of the concept are divergent. Discomforting

as this may seem for Lean proponents, there seems to be quite good agreement on the

characteristics that define the concept, leading to the conclusion that the concept is defined in

operational terms alone. Formulating a definition that captures all the dimensions of Lean is a

formidable challenge.

2.3 Statement of The Problem

TVS SRI CHAKRA Tyres, the Export department is facing frequent scraps of TRUCK tyres. A

single tyre scrap leads to loses in Direct cost (Rs50,000), Labour cost, Machine Productive time

(Thread Extruder , Bais cutting, Bead winding, Tyre Building, Curing etc). This study at TVS

SRICHAKRA has been done to identify problems faced in the Export Department particularly in

the Curing section and thereby to analyze, control and eliminate the occurrence of such problems

leading to continuous improvement.

2.4 Scope of Study

The scope of the study is to focus on cost reduction and time reduction at Curing section in

exports department by identifying and eliminating non-value added activities that takes place in the

export department at TVS Sri Chakra tires. To identify the scope towards the implementation of

lean in manufacturing organizations and its needs. It also brings into notice about the critical factors

responsible for the failure causes.

2.5 Objective of the Study

To understand the different types processes involved in the manufacturing of tires in TVS Sri Chakra.

To understand the application of FMEA in achieving Lean manufacturing.

To acquire knowledge about implementation of Lean practices.

To identify the factors leading to scrap in the CURING section.

To work towards continuous improvement.



2.6 Operational Definitions of the Concept

Lean Manufacturing:

Lean Manufacturing is an operational strategy oriented toward achieving the shortest possible cycle

time by eliminating waste. It is derived from the Toyota Production System and its key thrust is to

increase the value-added work by eliminating waste and reducing incidental work. The technique

often decreases the time between a customer order and shipment, and it is designed to radically

improve profitability, customer satisfaction, throughput time, and employee morale.

Waste:

Waste may be defined as any product, process or time which doesn’t add value to the end product and the customers.

Failure

The loss of an intended function of a device under stated conditions.

Failure Mode

The manner by which a failure is observed; it generally describes the way the failure

occurs.

Failure Effect

Immediate consequences of a failure on operation, function or functionality, or status of

some item.

Indenture Levels

An identifier for item complexity. Complexity increases as levels are closer to one.

Local Effect

The failure effect as it applies to the item under analysis.

Next Higher Level Effect



The failure effect as it applies at the next higher indenture level.

End Effect

The failure effect at the highest indenture level or total system.

Failure Cause

Defects in design, process, quality, or part application, which are the underlying cause of the

failure or that initiate a process that leads to failure.

Severity

The consequences of a failure mode. Severity considers the worst potential consequence of a

failure, determined by the degree of injury, property damage, or system damage that could

ultimately occur.

2.7 Methodology of Research

Type of Research

The type of research conducted in the study is a Applied Research

1) Application of knowledge to a case

2) Find alternative

3) Testing theory

4) Contribute new facts

2.7.1 Sources of Data

Primary Data

Primary data has been collected from a structured observation from real time workers in the shop

floor at the Exports Department. Interacting with all the sections labours and Engineers at TVS SRI

CHAKRA.

Secondary Data



Secondary datas has been collected from the company’s website and other relevant websites like

www.systems2win.com, www.leanmanufacturingshop.com, www.lssacademy.com and Production

& Operations management books.

2.8 Limitations Of Study

Since FMEA is effectively dependent on the members of the committee which examines

product failures, it is limited by their experience of previous failures. If a failure mode

cannot be identified, then external help is needed from consultants who are aware of the

many different types of product failure.

FMEA is thus part of a larger system of quality control, where documentation is vital to

implementation. General texts and detailed publications are available in forensic

engineering and failure analysis. It is a general requirement of many specific national and

international standards that FMEA is used in evaluating product integrity. If used as a top-

down tool, FMEA may only identify major failure modes in a system.

Fault tree analysis (FTA) is better suited for "top-down" analysis. When used as a "bottom-

up" tool FMEA can augment or complement FTA and identify many more causes and

failure modes resulting in top-level symptoms. It is not able to discover complex failure

modes involving multiple failures within a subsystem, or to report expected failure intervals

of particular failure modes up to the upper level subsystem or system.

Additionally, the multiplication of the severity, occurrence and detection rankings may

result in rank reversals, where a less serious failure mode receives a higher RPN than a more

serious failure mode. The reason for this is that the rankings are ordinal scale numbers, and

multiplication is not defined for ordinal numbers. The ordinal rankings only say that one

ranking is better or worse than another, but not by how much. For instance, a ranking of "2"

may not be twice as severe as a ranking of "1," or an "8" may not be twice as severe as a

"4," but multiplication treats them as though they are. See Level of measurement for further

discussion.

2.9 Chapter Scheme

CHAPTER 1 – INTRODUCTION:


http://en.wikipedia.org/wiki/Level_of_measurement

http://en.wikipedia.org/wiki/Ordinal_scale

http://en.wikipedia.org/wiki/Fault_tree_analysis

http://en.wikipedia.org/wiki/Top-down_and_bottom-up_design

http://en.wikipedia.org/wiki/Top-down_and_bottom-up_design

http://en.wikipedia.org/wiki/Failure_analysis

http://en.wikipedia.org/wiki/Forensic_engineering

http://en.wikipedia.org/wiki/Forensic_engineering

http://en.wikipedia.org/wiki/Quality_control


This chapter deals with the theoretical background of the study throwing light on the introduction to

lean concepts ,Goals, strategies, benefits’, FMEA analysis and its application.

CHAPTER 2 –RESEARCH DESIGN:

This chapter states the problem of the study; the objectives of the study, the scope, methodology,

tools for collecting data, a plan of analysis, and the limitations of the study. The chapter also

includes the operational definitions of the terms commonly used in the study, along with which the

chapter scheme is included.

CHAPTER 3 –INDUSTRY PROFILE:

This chapter gives information on Indian Tyre industry, an overview of TVS groups and Srichakra

TVS.

CHAPTER 4 –DATA ANALYSIS AND INTERPRETATION:

This chapter deals with analysis and interpretation of the data collected. The purpose of this chapter

is to find the failure mode in Curing section, Types of defects identified in Exports department at

Curing section at the month of April, Reasons behind the failure mode and the formation of FMEA

chart.

CHAPTER 5– FINDINGS AND SUGGESTIONS, FURTHER SCOPE FOR STUDY

This chapter deals with the overall findings and suggestion which are drawn based on the study of

Improvement measures at Sri Chakra TVS, Lean Concepts and FMEA chart.

CHAPTER 6–CONCLUSION

This chapter is the concluding chapter dealing with giving conclusion based on the Effectiveness of

Lean and also on FMEA chart.



CHAPTER 3

INDUSTRY PROFILE:

3.1 An Introduction to the Indian Tyre Industry

The Rs.20,000 crore Indian Tyre Industry, is highly raw material intensive and predominantly a

Cross Ply (or Bias) tyre manufacturing industry. It is highly concentrated wherein 10 large

manufacturers account for over 95% of the total tonnage production of 11.35 lakh M.T. It

produces all categories of tyres, except Snow Tyres and Aero Tyre for which there is no demand

domestically.

3.2 Key Influencers

The level of economic activity, performance of domestic automotive industry, and the faring

of the transport sector directly influence the performance of the tyre industry in India. With the

replacement segment dominating the overall tyre demand, the industry remains inherently



vulnerable to economic cycles. While radialisation has become the norm in the passenger car

segment, in the bus and truck tyre segment, its acceptance is still limited. Bus and truck

radialisation could emerge in the long term as the quality of roads improves and the

restrictions on overloading are better enforced. The practice of re-treading, which is gaining

increasing acceptance, could pose a challenge to replacement demand in the medium term.

The ability of the re-treading sector to capture potential replacement demand would depend on

the awareness among customers (of the benefits of retreading) and also the quality of

retreading done. Given the low levels of penetration of two-wheelers and passenger cars in the

country, OEM demand is likely to increase, which in turn would push up replacement demand

with a lag. Slowdown in automotive industry and global economy in general negatively

impacted the Indian tyre industry in 2009. The industry tonnage growth was only 2.19% during

first nine months of FY 2009, compared to 7.38% growth experienced during the same period

last year. Demand side was also severely affected as almost all auto manufacturers were

forced to adjust their production last year.



3.3 Role of Marketing

Over the years, tyre manufacturers have developed a vast marketing network using dealers and

depots and as such all types of tyres are now easily available even in the remotest corners of the

country. No doubt, international auto majors in India now roll out their vehicles using Indian

manufactured tyres.

3.4Sales and Profitability

The Indian Tyre Industry produced 821 lakh units of tyres garnering approximately Rs. 21,000

crore in FY 2009 -2010. The top players are now focusing on branding their products and

strengthening their distribution network so as to increase their market share. The industry

derives its demand from the automobile Industry. While the OEM (Original Equipment

Manufacturers) market off take is dependent on the new vehicle sales, replacement market

demand depends on the total population of vehicles on road, road conditions, vehicle scrapping

rules, overloading norms for trucks, average life of tyres and prevalence of tyre retreading.

3.5 Trends in Past years

As the economy in general; and automobile industry in specific slowed down in FY 2009,

the tyre demand too came under pressure. The industry production registered a 5 year

CAGR of 6.44% between FY 04-09. The largest category of Truck & Bus tyres recorded a 5

year CAGR of 2.96% (slower than the industry average) while Light Commercial Vehicle

(LCV), motorcycle and car tyre categories grew at 6.07%, 10.70% and 6.90% respectively

(relatively faster than the industry average).

Off the Road (OTR) tyre category (customized tyres) which fetches a higher margin compared

to other tyre categories, was the fastest growing. The OTR tyre category had registered a 5 year

CAGR of over 8.85% in the last five years. Most of the top players increased their capacity



Also in the face of global slowdown and stiff Chinese competition, the export market off take

declined by 9.82% during this period.

On the face of demand-side pressures, the tyre industry saw production adjustments from all the

major players in the last couple of months. The government too tried to provide external

stimulus by effecting 6% excise duty cut across industries (the excise duty for tyres was

brought down from 14% to 10% w.e.f. December 7, 2008, and then further reduced to 8%

w.e.f. February 25,2009). In all the gloom; one silver lining for the industry was the easing

of the raw material prices from September 2008 onwards. However, their future movement

still remains uncertain. Based on data from the Rubber Board, natural rubber prices have risen

about 50% in the last 6-7 months. In fact, prices in the Indian market are presently ruling 5-6%

higher than the same in international markets. As a result, tyre makers are facing significant rise

in cost production. This has forced the industry to begin hiking prices in an attempt to keep

the already thin margins intact.

Tyre majors have already hiked prices. Moreover, due to shortfall in domestic supply

and increasing gap between domestic and international prices of rubber, the tyre

manufacturers have increased the import of natural rubber. According to estimates

by Automotive Tyre Manufacturers Association (ATMA), tyre producers are likely to

import 50% of their total natural rubber consumption due to tight domestic supply. With

profitability of tyre companies having a strong correlation to raw material prices and as

these companies operate on thin margins, this would remain an area of concern.

3.6 Current status & Future Trends

As regards to the demand scenario, the poor demand growth in FY 2009 - 2010 was primarily

on account of decline in OEM production. Continuation of poor volume growth could affect the

profitability further. Despite these challenges, according to CARE (Credit Rating &

Research) Ltd., while the industry may register a low tonnage growth in FY 2009, the

long term prospective seems to be bright. They expect the industry to experience a

CAGR of approximately 8.21% between FY08 to FY13.

Automotive companies have started experiencing increasing sales and raw material prices

are stabilizing which will boost tyre sales over the coming months. However, experts



suggest there will be some time lag before profitability.

3.7 Towards the Future – “Radialisation” in India

Radialisation in India though in its infancy in T&B tyre category; is making inroads. Most

manufacturers have capex plans for radial T&B tyres with no new capacity being added for

bias tyres. This indicates that the industry foresees radialisation to take further hold in the

T&B tyre category. "Rate of radialisation is actually an index of the status of road

development, vehicle engineering and the economy in general". Notwithstanding the problem

areas, constraints and limitations, the tyre companies have kept pace with the technological

improvements that radialisation signifies and offer state-of-the-art product (tyres),

comparable to the best in the world.

• Radialisation can be aptly classified as the most important innovation in tyre

technology.

Despite its several advantages (additional mileage; fuel saving; improved driving) radialisation

in India earlier did not catch on at a pace that was expected, since its introduction way

back in 1978. This could be attributed due to several factors, viz. Indian roads generally not

being suitable for ideal plying of radial tyres; (older) vehicles produced in India not having

suitable geometry for fitment of radial tyres (and hence the general, and wrong, perception that

radial tyres are not required for Indian vehicle; unwillingness of consumer to pay higher price

for radial tyres etc.

• However, the situation has radically changed in recent years, especially for the

passenger car tyre segment where radialisation has crossed 98% mark and is

expected to reach

100% in two to three years. In the Medium and Heavy Commercial vehical

segment current level of radialisation is upto 8%, and that in the LCV segment is

estimated at

18%.

• A few years back a beginning was made in Radialisation of truck and bus and LCV

tyres and this process is gaining momentum.



3.8 Major Players and Market Shares Fig no 3.1

major

players include MRF

Ltd. which is the

marke

t

closel

y

leader (22% market share)

by Apollo Tyres Ltd. (21%).

followed

The other

5

MRF Tyres

Apollo Tyres

major

players are JK Tyre

& Industries Ltd.

74 22

J.K. Tyres

(18%),

Ceat Ltd. (13%),

Birla Tyres (10%), 10 Ceat

Goodyear (7%) and Bridgestone (5%). On an 13

2118

average, 55% of the production is for replacement

market, followed by 29.8% sold to OEMs

directly and the remaining is exported.

Birla

Goodyear

Bridgeston

e Oth


3.9 Swot Analysis for the Tyre Industry

Strengths

Established brand names (key in the replacement market)

Extensive distribution networks - For example, Apollo Tyres has more than 118

district offices, 12 distribution centres and 4,250 dealers.

Good R&D initiatives by top players.

Weaknesses

Cost Pressures - The profitability of the industry has high correlation with the prices of key

raw materials such as rubber and crude oil, as they account for more than 70% of the total

costs.

Pricing Pressures – The huge raw material costs have resulted in pressure on the

realisations and hence, the players have been vouching to increase the prices, although, due to

competitive pressures, they have not been able to pass on the entire increase to the customer.

Highly capital intensive - It requires about Rs 4 billion to set up a radial tyre plant

with a capacity of 1.5 million tyres and around Rs 1.5-2 billion, for a cross-ply tyre plant of a 1.5

million tyre-manufacturing capacity.

Opportunities

Growing Economy leads to Growing Automobile Industry leads to Increasing OEM

demand that in turn leads to Subsequent rise in replacement demand.

With continued emphasis being placed by the Central Government on development of

infrastructure, particularly roads, agricultural and manufacturing sectors, the Indian

economy and the automobile sector/ tyre industry are poised for an impressive

growth. Creation of road infrastructure has given, and would increasingly give, a

tremendous fillip to road transportation, in the coming years. The Tyre industry

would play an important role in this changing road transportation dynamics.

Access to global sources for raw materials at competitive prices, due to economies of

scale. Steady increase in radial Tyres for MHCV’s and LCV’s.

Threats

Continuous increase in prices of natural rubber, which accounts for nearly one third of

total raw material costs.

Cheaper imports of Tyres, especially from China, selling at very low prices, have

been posing a challenge. The landed price is approximately 25% lower than that of the

corresponding Indian Truck/ LCV tyres. Imports from China now constitute around 5%

of market share.

With crude prices scaling upwards, added pressure on raw material prices is expected

Ban on Overloading, leading to lesser wear and tear of tyres and subsequent

slowdown in demand. However, this would only be a short-term negative.

Cyclical nature of automobile industry.

3.10 COMPANY PROFILE

TVS Group is one of India’s oldest business groups. It is a giant conglomerate with

presence in diverse fields like automotive component manufacturing, automotive dealerships and

electronics. Today, there are over thirty companies in the TVS Group, employing more than

40,000 people worldwide and with a turnover in excess of USD 2.2 billion.

TVS Group originated as a transport company in 1911. TV Sundaram Iyengar and Sons Limited

are the parent and holding company of the TVS Group. TV Sundaram Iyengar and Sons Limited

have the following three divisions.

TVS AND SONS

TVS and Sons is the largest automobile distribution company in India. It distributes

Heavy Duty Commercial Vehicles, Jeeps and Cars. TVS and Sons represent premier automotive

companies like AshokLeyland, Mahindra and Mahindra Ltd., and Honda.

SUNDARAM MOTORS

Sundaram Motors distributes Heavy Duty Commercial Vehicles, Cars, and auto spare

parts for several leading manufacturers. The company is also the dealer for Ashok Leyland,

Honda, Fiat, Ford and Mercedes Benz.

MADRAS AUTO SERVICE

Madras Auto Service distributes automotive spare parts for all leading manufacturers.

OTHER MAJOR COMPANIES

TVS Motor Company Limited is one of the largest two-wheeler manufacturers in India.

It manufactures Motorcycles.

BREAKES INDIA LIMITED

Brakes India is a joint venture between T V Sundaram Iyengar and Sons Ltd., and Lucas

Industries Plc., UK. The company manufactures braking equipment for automotive and non-

automotive applications.

SUNDARAM POLYMERS DIVISION

Sundaram Polymers Division manufactures Engineering Plastic compounds for various

applications.

HARITA FINANCE LIMITED

Harita Finance Ltd. is a finance company under the TVS Group. It deals in retail finance,

hire purchase, leasing and bill discounting.

INDIA NIPPON ELECTRICALS LIMITED

It is a joint venture between Lucas Indian Service and Kokusan Denki Co Ltd., Japan.

The Company manufactures Electronic Ignition Systems for two wheelers and portable gensets.

IRIZAR TVS (P) TD

IRIZAR TVS (P) Ltd., is a joint venture between Sundaram Industries Ltd., Ashok

Leyland Ltd., and IRIZAR S. Co-op of Spain. The company builds bus bodies for export and

domestic market.

LAKSHMI AUTO COMPONENTS LIMITED

The company is a subsidiary of TVS-Suzuki. It manufactures gears, crankshafts and

connecting rods for TVS-Suzuki motorbikes and mopeds.

LUCAS INDIA SERVICE

Lucas Indian Service is a wholly owned subsidiary of Lucas-TVS Ltd., engaged in the

sales and service of auto-electrical and fuel injection equipment.

SUNDARAM-CLAYTON LIMITED

Sundaram - Clayton Ltd., manufactures complete range of air brake actuation system -

compressors, actuators, valves, brake chambers, spring brakes, slack adjusters, couplings, hoses,

switches and vacuum boosters for light, medium and heavy commercial vehicles and trailer.

Foundry Division manufactures aluminum gravity and pressure die-castings.

TVS SRICHAKRA TYRES

TVS Srichakra is one of the leading two and three-wheeler tyre manufacturer in India

rolling out over 11 million tyres per annum. Company is part of US $5 billion TVS Auto

Ancillary group, which is largest in India.

Incorporated in 1982, the company manufactures a complete range of Two and Three

wheeler Tyres and Tubes for the domestic market and Industrial Pneumatic tyres, Farm &

Implements tyres, Skid steer tyres, Multipurpose tyres, Floatation tyres etc., for the export

market, at its state-of-art manufacturing facility at Madurai in Tamilnadu. Spread over an area of

2.5 lakhs Sq.mts. The manufacturing unit at Madurai employees over 2000 people.

TVS Tyres is one of the major suppliers to all leading original equipment manufacturers

namely TVS Motors, Hero Honda, Bajaj Auto and Yamaha Motors and has a strong network of

over 2050 dealers and 23 depots across the country to cater to the aftermarket. The company is a

global player, exporting to USA, Europe, Africa, South America and South East Asia.

Accredited on 1996 with ISO 9001 certifications, TVS tyres adopted strong quality standards

from its inception and these benchmarks were further strengthened with the certification of ISO

14001.The company has other practices like Six Sigma and Lean Manufacturing Techniques in

place to abide by their high quality standards. TVS tyres were also the winner of the prestigious

TPM Excellence Award in 2003 and TPM Consistency Award in 2005.

3.11 Tyre Manufacturing

Pneumatic tyres are manufactured according to relatively standardized processes

and machinery, in around 450 tyre factories and the world. With over

1 billion tyres manufactured worldwide annually, the tyre industry is the major consumer

of natural rubber. Tyre factories start with bulk raw materials such as rubber, carbon

black, and chemicals and produce numerous specialized components that are assembled

and cured. This article describes the components assembled to make a tyre, the various

materials used, the manufacturing processes and machinery, and the overall business

model.

Fig 3.2 Inner view of tyre

The tyre is an assembly of numerous components as shown in figure 2 which are

then built up on a drum and then cured in a press under heat and pressure. Heat

facilitates a polymerization reaction that crosses links rubber monomers to create long

elastic molecules. These polymers create the elastic quality that permits the tyre to be

compressed in the area where the tyre contacts the road surface and spring back to its

original shape under high-frequency cycles.

Inner Liner

The inner liner is an extruded halo buty1 rubber sheet compounded with additives

that result in low air permeability. The inner liner assures that the tyre will hold high-

pressure air inside, without the air gradually diffusing through the rubber structure.

Body Ply

The body ply is a calendared sheet consisting of one layer of rubber one layer of

reinforcing fabric, and a second layer of rubber. The earliest textile used was cotton; later

materials include rayon, polyester, and Kevlar. Passenger tyres typically have one or two

body plies. Body plies give the tyre structure strength.

Beads

Beads are bands of high tensile-strength steel wire encased in a rubber compound.

Bead wire is coated with special alloys of bronze or brass that protects the steel from

corrosion. Beads are inflexible and inelastic, and provide the mechanical strength to fit

the tyre to the wheel.

Apex

The apex is a triangular extruded profile that mates against the bead. The apex

provides a cushion between the rigid bead and the flexible inner liner and body ply

assembly.

Belt Package

Belts are calendared sheets consisting of a layer of rubber, a layer of closely

spaced steel cords, and a second layer of rubber. The steel cords are oriented radially in

radial tyre construction, and at opposing angles in bias tyre construction. Belts give the

tyre strength and dent resistance while allowing it to remain flexible. Passenger tyres are

usually made with two or three belts.

Tread

The tread is a thick extruded profile that surrounds the tyre carcass. Tread

compounds include additives to impart wear resistance and traction in addition to

environmental resistance. The tread is the part of the tyre which comes in contact with the

road surface. The tread is a thick rubber, or rubber/composite compound formulated to

provide an appropriate level of traction that does not wear away too quickly. The tread

pattern is characterized by the geometrical shape of the grooves, lugs, voids and sipes.

Tread wear

The tread wear grade describes how long the tyre manufacturers expect the tyre to

last. A Course Monitoring tyre (the standard tyre that a test tyre will be compared to) has

a rating of “100”. If a manufacturer assigns a tread wear rating of 200 to a new tyre, they

are indicating that they expect the new tyre to have a useful lifespan that is 200% of the

life of a Course Monitoring tyre. The “test tyres” are all manufacturer dependant. Brand

A’s rating of 500 is not necessarily going to give you the same mileage rating as Brand

B’s tyre of the same rating.

Tread Lug

Tread lugs provide the contact surface necessary to provide traction. As the

treadlug enters the road contact area, or footprint, it is compressed. As it rotates through

the footprint it is deformed circumferentially. As it exits the footprint, it recovers to its

original shape.

Tread Void

Tread voids provide space for the lug to flex and deform as it enters and exits the

footprint. Voids also provide channels for rainwater, mud, and snow to be channeled

away from the footprint. The void ratio is the void area of the tyre divided by the tyre

tread area. Low void areas have high contact area and therefore higher traction on clean,

dry pavement.

Rain Groove

The rain groove is a design element of the tread pattern specifically arranged to

channel water away from the footprint. Rain grooves are circumferential in most truck

tyres. Many high performance passenger tyres feature rain grooves that are angled from

the centre toward the sides of the tyre.

Shoulder

The shoulder is that part of the tyre at the edge of the tread as it makes transition to

the sidewall.

Sipe

Tread lugs often feature small narrow voids, or sipes, that improve the flexibility

of the lug to deform as it traverses the footprint area. This reduces in the lug and reduces

heat buildup. Sipes also provide greater traction in wet or icy conditions.

Contact Patch

The Contact patch, or footprint, of the tyre, is merely the area f the tread which is

in contact with the road surface. This is the area which transmits forces between the tyre

and the road via friction.

Side Wall

The side wall is that part of the tyre that bridges between the tread and bead. The

sidewall is reinforced with rubber and fabric plies that provide for strength and flexibility.

It transmits the torque applied by the drive axle to the tread in order to create traction.

Sidewall, in conjunction with the air inflation, also supports the load of the vehicle.

Sidewalls are molded with manufacturer-specific detail; government mandated warning

labels, and other consumer information, and other consumer information, and sometimes

decorative ornamentation, like whitewalls.

Fig 3.3 Sidewall

Inner Tube

Almost all bicycle tyres, many motorcycle tyres, and many tyres for large vehicles

such as uses, heavy trucks and tractors are designed for use with inner tubes. Inner tubes

are torus-shaped balloons made from an impermeable materials, such as soft, elastic

synthetic rubber to prevent air leakage.

Wheel

Tyres are mounted to wheels that bolt to the hub. Automotive wheels are typically

made from pressed and welded steel, or a composite of lightweight metal alloys, such as

aluminum or magnesium. These alloy wheels may be either cast or forged. A decorative

hubcap and trim ring may be placed over the wheel.

Valve Stem

The valve stem is a tube made of steel or rubber with a metal valve used to inflate

the tyre with air. Valve stems usually protrude though the wheel for easy access for

inflation. Tyres are inflated through a valve, typically a Schrader valve on automobiles

and most bicycle tyres, or a Presta valve on high performance bicycles. the rubber in

valve stems eventually degrades. Replacement of the valve stem at regular intervals

reduces the chance of failure.

Fig. 3.4 Valve Stem

3.12 Manufacturing Process

Tyre plans are traditionally divided into five departments that perform special

operations. These usually act as independent factories within a factory. Large tyre

makers may set up independent factories on a single site, or cluster the factories locally

across a region.

Compounding And Mixing

Compounding is the operation of bringing together all the ingredients required to

mix a batch of rubber compound. Each component has a different mix of ingredients

according to the properties required for that component.

Mixing is the process of applying mechanical work to the ingredients in order to

blend them into a homogeneous substance. Internal mixers are often equipped with two

counter-rotating rotors in a large housing that shear the rubber charge along with the

additives.

After mixing, the rubber charge is dropped into a chute and fed by an extruding

screw into a roller die. Alternatively, the batch can be dropped onto an open rubber mill

batch off system. A mill consists of twin counter-rotating rolls, one serrated, that

provides additional mechanical working to the rubber and produces a thick rubber sheet.

The sheet is pulled off the rollers in the form of a strip. The strip is cooled, dusted with

talc, and laid down into a pallet bin.

The ideal compound at this point would have a highly uniform material dispersion;

however in practice there is considerable non-uniformity to the dispersion. This is due to

several causes, including hot and cold spots in the mixer housing and rotors, excessive

rotor clearance, rotor wear, and poorly circulating flow paths. As a result, there can be a

little more carbon black here, and a little less there, along with a few clumps of carbon

black elsewhere, that are not well mixed with the rubber or the additives.

Mixers are often controlled according to the power integration method, where the

current flow to the mixer motor is measured, and the mixing terminated upon reaching a

specified total amount to mix energy imparted to the batch.

Component Preparation

Components fall into three classes based on manufacturing process: calendaring,

extrusion, and bead building.

The extruder machine consists of a screw and barrel, screw driver, heaters, and a

die. The extruder applies two conditions to the compound: heat and pressure. The

extruder screw also provides for additional mixing of the compound through the shearing

action of the screw. The compound is pushed through a die, after which the extruded

profile is vulcanized in a continuous oven, cooled to terminate the vulcanization process,

and either rolled up on a spool or cut to length. Tyre treads are often extruded with four

components in a quadraplex extruder, one with four screws processing four different

compounds, usually a base compound, core compound, tread wing compound. Extrusion

is also sued for sidewall profiles and inner liners.

The calendar is a set of multiple large-diameter rolls that squeeze rubber

compound into a thin sheet, usually of the order of 2 meters wide. Fabric calendars

produce an upper and lower rubber sheet with a layer of fabric in between. Steel

calendars do so with steel cords. Calendars are used to produce body plies and belts. A

creel room is a facility that houses hundreds of fabric or wire spools that are fed into the

calendar. Calendars utilize downstream equipment for shearing and splicing calendared

components.

Tyre Building

Tyre building is the process of assembling all the components onto a tyre building

drum. Tyre-building machines (TBM) can be manually operated or fully automatic.

Typical TBM operations include the first-stage operation, where inner liner, body plies,

and sidewalls are wrapped around the drum, the beads are placed, and the assembly

turned up over the bead. In the second stage operation the belt package and tread are

applied and the green tyre is inflated and shaped.

All components require splicing. Inner liner and body plies are spliced with a

square-ended overlap. Tread and sidewall are joined with a skived splice, where the

joining ends are bevel-cut. Belts are spliced end to end with nooverlap. Splices that are

too heavy or non-symmetrical will generate defects in force variation, balance, or bulge

parameters. Splices that are too light or open can lead to visual defects and in some cases

tyre failure. The final product of the TBM process is called a green tyre, where green

refers to the uncured state.

Pirelli tyre developed a special process called MIRS that uses robots to position

and rotates the building drums under stations that apply the various components, usually

via extrusion and strip winding methods. This permits the equipment to build different

tyre sizes in consecutive operations without the need to change tooling or setups. This

process is well suited to small volume production with frequent size changes.

The largest tyre makers have internally developed automated tyre-assembly

machines in an effort to create competitive advantages in tyre construction precision,

high production yield, and reduced labor. Nevertheless there is a large base of machine

builders who produce tyre-building machines.

Curing

Curing is the process of applying pressure to the green tyre in a mold in order to

give it its final shape, and applying heat energy to stimulate the chemical reaction

between the rubber and other materials. In this process the green tyre is automatically

transferred onto the lower mold bead seat, a rubber bladder is inserted into the green tyre,

and the mold closes while the bladder inflates. As the mold closes and is locked the

bladder pressure increases so as to make the green tyre flow into the mold, taking on the

tread pattern and sidewall lettering engraved into the mold. the bladder is filled with a

recirculation heat transfer medium such as steam, hot water, or insert gas. Temperatures

are in the re of 350 degrees Fharenheit with pressures around 350 PSI. Passenger tyres

cure in approximately 15 minutes. At the end of cure the pressure is bled down, the mold

opened, and the tyre stripped out of the mold. The tyre may be placed n a PCI, lr post-

cure inflator, that will hold the tyre fully inflated while it cools. There are two generic

curing ress types, mechanical and hydraulic. Mechanical presses hold the mold closed

via toggle linkages, while hydraulic presses use hydraulic oil as the prime mover for

machine motion, and lock the mold with a breech-lock mechanism. Hydraulic presses

have emerged as the most cost-effective because the press structure does not have to

withstand the mold-opening pressure and can therefore be relatively light weight. There

are two generic mold types, two-piece molds and segmental molds. Large off-road tyres

are often cured in ovens with cure times approaching 24 hours.

Final Finish

After the tyre has been cured, there are several additional operations. Tyre

uniformity measurement is a test where the tyre is automatically mounted on wheel

halves, inflated, run against a simulated road surface, and measured for force variation.

Tyre balance measurement is a test where the tyre is automatically placed on wheel

halves, rotated at a high speed and measured for imbalance.

Large commercial truck/bus tyres, as well as some passenger and light truck tyres,

are inspected by X-ray machines that can penetrate the rubber to analyze the steel cord

structure.

In the final step, tyres are inspected by human eyes for numerous visual defects

such as incomplete mold fill, exposed cords, blisters, blemishes, and others.

3.13 Tyre Manufacturing Process Flow Diagram:

Fig no 3.5

CHAPTER 4

ANALYSIS AND INTERPRETATION

4.1 Tools & Techniques For Study

Failure Mode & Effect Analysis

A failure modes and effects analysis (FMEA) is a procedure in product development, systems

engineering and operations management for analysis of potential failure modes within a system

for classification by the severity and likelihood of the failures. A successful FMEA activity helps

a team to identify potential failure modes based on past experience with similar products or

processes, enabling the team to design those failures out of the system with the minimum of

effort and resource expenditure, thereby reducing development time and costs. Because it forces

a review of functions and functional requirements, it also serves as a form of design review. It is

widely used in manufacturing industries in various phases of the product life cycle and is now

increasingly finding use in the service industry. Failure modes are any errors or defects in a

process, design, or item, especially those that affect the intended function of the product and or

process, and can be potential or actual. Effects analysis refers to studying the consequences of

those failures.

In general, Failure Modes, Effects and Criticality Analysis (FMEA / FMECA) requires the

identification of the following basic information:

Item(s)

Function(s)

Failure(s)

Effect(s) of Failure

Cause(s) of Failure

Current Control(s)

Recommended Action(s)

Plus other relevant details

http://en.wikipedia.org/wiki/Design_review



Most analyses of this type also include some method to assess the risk associated with the issues

identified during the analysis and to prioritize corrective actions. Two common methods include:

Risk Priority Numbers (RPNs)

Criticality Analysis (FMEA with Criticality Analysis = FMECA)

Pre Work

The process for conducting an FMEA is typically developed in three main phases, in which

appropriate actions need to be defined. Before starting with an FMEA, several other techniques

are frequently employed to ensure that robustness and history are included in the analysis.

A robustness analysis can be obtained from interface matrices, boundary diagrams,

and parameter diagrams. Failures are often found from external 'noise factors' and from shared

interfaces with other parts and/or systems.

Typically, a description of the system and its function is developed, considering both intentional

and unintentional uses.


A block diagram of the system is often created for inclusion with the FMEA, giving an overview

of the major components or process steps and how they are related. These are called logical

relations around which the FMEA can be developed.

The primary FME document or 'worksheet' lists all of the items or functions of the system in a

logical manner, typically based on the block diagram.

Basic Analysis Procedure For Fmea Or Fmeca

The basic steps for performing an Failure Mode and Effects Analysis (FMEA) or Failure Modes,

Effects and Criticality Analysis (FMECA) include:

Assemble the team.

Establish the ground rules.

Gather and review relevant information.

Identify the item(s) or process(es) to be analyzed.

Identify the function(s), failure(s), effect(s), cause(s) and control(s) for each item or

process to be analyzed.

Evaluate the risk associated with the issues identified by the analysis.

Prioritize and assign corrective actions.

Perform corrective actions and re-evaluate risk.

Distribute, review and update the analysis, as appropriate.

Risk Evaluation Methods

A typical failure modes and effects analysis incorporates some method to evaluate the risk

associated with the potential problems identified through the analysis. The two most common

methods, Risk Priority Numbers and Criticality Analysis, are described next.

Risk Priority Numbers

To use the Risk Priority Number (RPN) method to assess risk, the analysis team must:

Rate the severity of each effect of failure.

Rate the likelihood of occurrence for each cause of failure.

Rate the likelihood of prior detection for each cause of failure (i.e. the likelihood of

detecting the problem before it reaches the end user or customer).

Calculate the RPN by obtaining the product of the three ratings:

RPN = Severity x Occurrence x Detection

The RPN can then be used to compare issues within the analysis and to prioritize problems for

corrective action. This risk assessment method is commonly associated with Failure Mode and

Effects Analysis (FMEA).

Criticality Analysis

The MIL-STD-1629A document describes two types of criticality analysis: quantitative and

qualitative. To use the quantitative criticality analysis method, the analysis team must:

Define the reliability/unreliability for each item and use it to estimate the expected

number of failures at a given operating time.

Identify the portion of the item’s unreliability that can be attributed to each potential

failure mode.

Rate the probability of loss (or severity) that will result from each failure mode that may

occur.

Calculate the criticality for each potential failure mode by obtaining the product of the

three factors:

Mode Criticality = Expected Failures x Mode Ratio of Unreliability x Probability of

Loss

Calculate the criticality for each item by obtaining the sum of the criticalities for each

failure mode that has been identified for the item.

Item Criticality = SUM of Mode Criticalities

To use the qualitative criticality analysis method to evaluate risk and prioritize corrective actions,

the analysis team must:

Rate the severity of the potential effects of failure.

Rate the likelihood of occurrence for each potential failure mode.

Compare failure modes via a Criticality Matrix, which identifies severity on the

horizontal axis and occurrence on the vertical axis.

These risk assessment methods are commonly associated with Failure Modes, Effects and

Criticality Analysis (FMECA).

4.2 Analysis & Interpretation

Export Tyre Scrap – April ‘12

Types of Defects Identified in CURING Section

DEFECTS NOS. CUM % PPM

Bladder cut 65 31.86 3021HW Pressure Drop 17 40.20 790HP Drop 19 49.51 883External Under cure 7 52.94 325OCL 10 57.84 465Blow 11 63.24 511Open Mould 8 67.16 372Bead Under cure 6 70.10 279OD Variation 7 73.53 325Heavy flash 6 76.47 279Cord Grooving Blow 5 78.92 232Panel Slip 4 80.88 186Wrong moulding 4 82.84 186HP Raising problem 3 84.31 139PCI Burst 2 85.29 93Side Wall Blow 2 86.27 93Flash FM 2 87.25 93Internal Under cure 2 88.24 93Bead Buckle 2 89.22 93Blend edge 2 90.20 93Cord visible 2 91.18 93SW week 2 92.16 93PCI Delay 2 93.14 93HW Not Entry 2 94.12 93SW Crack 1 94.61 46Cord Discord 1 95.10 46Bead Damage 1 95.59 46Inner Under cure 1 96.08 46Clamp slip 1 96.57 46Thin Bead 1 97.06 46

SW Blow 1 97.55 46Cord Grooving 1 98.04 46Inner Bearness 1 98.53 46Under cure 1 99.02 46Bead Drop 1 99.51 46Ply Blow 1 100.00 46TOTAL 204 9480

No - Number of Defective tyres

Cum - Cumulative Percentage of Defects

PPM - Parts per Million

4.4 Bar Chart showing the Types of Defects

PRODUCTION PLAN :25273

ACTUAL PRODUCTION:21519

TOTAL SCRAPS:204

Efficency :85.1%

4.3 FMEA Chart

CHAPTER 5

FINDINGS, CONCLUSION & SUGGESTIONS

5.1 Findings

Implementation of Lean Concepts in TVS SRI CHAKRA has helped in understanding the

reasons behind customer satisfaction and theoretical profits of the company. The implementation

of Lean has helped in reducing the scrap and reducing the lead time of tyre manufacturing so as

to provide an improved efficiency. FMEA analysis was carried out and reason behind the

occurrence of scrap has been found . The finding’s, suggestions and conclusion is based on the

objectives mentioned in the dissertation work.

The Process of the Mother Feeders like Thread extrusion, Bias cutting, Bead winding,

Tyre Building and Curing are found to be critical.

The productivity of the TVS Sri Chakra has been found to experience a down fall in the

past few months.

Labours in the shop floor experience Over Burden due to the heat generated in the

manufacturing section.

The amount of scraps found in all the section of exports department say(Thread

extrusion, Bias cutting, Bead Winding, Tyre Building& curing) has been found

increasing.

Particularly in curing section the types of defects found in tyres has been increased

considerably.

FMEA has been an effective tool in reducing the risk from the identified higher level to a

lower level.

The reasons behind the occurrence of tyre scraps has been identified.

The Percentage of Major accidents happen inside the Exports department is Less.

Labours feel a considerable amount of safety inside the shop floor.

The Machines in the export department are found to be depriciated with reasonably high

amount of wear & tear.

The Demand for Tyres in the Export department is increasing day by day.

Construction of new Export department is under process.

The Labours are highly facilitated by providing with Quality foods at the Cheapest rate.

5.2 Conclusion:

As TVS Sri Chakra is a intensive manufacturing unit, the possible occurrence of different

type of wastes are found to be high. So it a need for every manufacturing organization to

become lean thereby increasing its productivity and saving its valuable resources spent. As

the Productivity is highly biased on Curing section in a tyre industry it is highly needed

reduce the amount of scrap occur in the curing section. FMEA is one of the effective tools of

lean to identify the scrap, spot the reasons, rate the value of severity & draw the action plan

to reduce its occurrences. After Implementation of FMEA the Risk Priority number for each

defects has been found to decrease reasonably to a degree of 25%. Hence froth Sri Chakra

TVS has been found to become lean and work towards continuous improvement.

5.3 Suggestions:

The Recommendations are as follows.

The company should Focus on Total productive Maintenance to improve machine

availability and to improve the life of machines.

The company should rate the Safety hazards and create a safety check list.

Shop Floor ambience should be altered in such a way that the workers are joyful and

energetic.

The company should install a ACOUSTIC insulation to absorb the noise produced in the

plant and to keep the outside noise out.

The R&D department should give effective suggestions to improve the machines life and

overall productivity.

Internal audit should be done on a regularly basis to spot and eliminate the defects.

All possible aspects of Lean should be implemented so as to improve efficiency and work

towards zero defects.

Training on cleaning and maintaining of machine parts have to be carried out in order to

ensure smooth production process and to increase the life of the machine.

Proper training on the modern aspects of production, techniques and its impact on

productivity should be given to shop floor workers.

Suggestions Boxes should be provided at each department to collect the valid inputs on

the employees.

BIBLIOGRAPHY:

Books:

a. Yasuhiro Monden, ed. Toyota Production System, 3rd Edition, Inst of Industrial

Engineers, December 1 1998

b. K.Ashwathappa, ed. Operations & Production management, 8th Edition, Mumbai

Himalaya Publishing House, 2009

c. Andrew.P.Dillon, ed. The sayings of Shigeo Shingo Key Strategies for Plant

Improvement 1st edition, Productivity Press, 1987

d. Mike Rother, ed. vsm getting started set, 8th Edition , Lean Enterprise Institute,

Inc , 2009.

Websites:

a. www.elseinc.com/training/lean-overview/implement-lean-manufacturing/

b. www.wisc-online.com/objects/ViewObject.aspx?ID=ORD103

c. www.leanmanufacturingshop.com

d. www.lssacademy.com/2007/06/28/10-steps-to-creating-a-fmea/

e. www.systems2win.com/solutions/value_stream.htm

FMEA analysis

Documents

primary fme

sri chakra

tvs sri chakra

1629a document

assign corrective

highest indenture

risk priority

called logical