Transcript
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
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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
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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
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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.
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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)
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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
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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.
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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
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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.
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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.
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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
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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.
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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
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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
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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,
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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.
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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
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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
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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:
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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.
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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
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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.
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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
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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
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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.
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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
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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
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
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