1. Preamble

1.1 Introduction To The Project

All business organization’s prime motive is to satisfy the customer requirement

and attain a distinguished position in the world market. During the last few years, the

automobile market has been witnessing an increased competition and rising demand for the

sophisticated seating systems due to globalisation. Due to this ever changing demand and

competition among the companies in these industries, there is tremendous pressure built to

look for newer designs, cost reduction techniques, improving the product quality and process

the products on Just In Time (JIT) manufacturing system, in order to be competitive.

Therefore, it is vital to improve the availability, utilization and quality of the product and meet

the demand of the customer on time without fail.

To manage all the tough situations and be a leader in the market, organisations

should concentrate on the following

Productivity

Quality

Cost

Delivery

Morale &

Waste elimination

The main objectives behind this is to achieve the business growth, customer

delight becomes the prime focus for which the above said 6 parameters need to be improved

to world class levels to make the company to move to great heights in the competitive market

1.2 Problem on hand

In the growing business scenario, where recession has affected some of the major OE’s,

the need for cost cut & cost saving becomes a prime responsibility of any organization

Realization of the actual business against the required growth plays a major role for the

development of any organization. Harita seating being a prime company in the manufacturing

of seats supplies more than 8000 seats to TVS motor per day for their two wheelers.

Thus it gave me a hint for project to be undertaken in the following area where VA/VE

in the two wheeler seat assembly will definitely give a cost saving there by benefiting the

organization.

1

1.3 Importance of the problem

TVS Motor (TVSM) confirmed their production ramping up plan during

the third quarter of 2011- 12. TVSM has demanded for the cost reduction of the products due

to the increase in the quantity of production also.

1.3.1 Need for study

We are supplying two wheeler seats to our prestigious customer TVS

motor company located in Hosur & Mysore with 100% business share for the year 2000

onwards .The supplies are made on just in time (JIT) basis every hour .The business with them

has been consistently growing since then from 2,700 seats per day in the year 2002-03 to 6,400

upto 2009-10. The projected volume for 2011-12 is 8,400 seats per day .So from the projected

volume we got a hint that DOE in this area will definitely give a cost optimization there by

benefiting the organization. `

Table 1.3.1: Model wise Seat requirement by TVSM / Day

2

fig 1.3.1.a Year wise Seat requirement by TVSM / Day

Fig 1.3.1 .b : Two Wheeler Demand Graph

3

Model wise Seat requirement per day

2000 1500

900700 600 600 500 500 400 400 300

0

400

800

1200

1600

2000

StarSport

XLHD StarDlx

XLN U68 N45 Max100

XL -HD

N90 N17 U41

Model wise

Qty

1.4 PRIMARY OBJCTIVE

The main objective of this project is to find the optimal method of two-wheeler seat

assembly using Design of Experiment (DOE).

1.5 SECONDARY OBJECTIVES

To identify the existing methodology of material composition.

Introducing Design of Experiment (DOE), in order to obtain the best method.

To make a comparative study of existing and proposed methodology.

Conclusion

1.6 SCOPE OF THE PROJECT

The scope of the project is to find the optimal method of two-wheeler

seat assembly using Design of Experiment (DOE).

The objective of this project is to retain the basic functionality of Cushion

manufacturing and reduction of the manufacturing cost.

1.7 EXPECTED DELIVERABLES

a. This project yield gains in terms of cost, quality, delivery, time etc.

b. Increase in the contribution of products

c. Reduced in- house as well as customer end line rejections.

d. This project can result in substantial benefits to the customer.

e. Similar study can be extended to the other products in the organization where

there is a real need of the cost optimization.

4

2.0 DETAILS OF THE ORGANISATION:

Harita Seating Systems Limited (HSSL) (Formerly known as Harita

Grammer Limited) is an automotive ancillary unit situated at Belagondapalli village near

industrial town of Hosur, (A Suburb of Bangalore) Tamilnadu.

2.1 Company Profile

Shri T S Srinivasan, youngest son of Shri T V Sundaram Iyengar, the

founder of TVS group of companies, conceived the Harita Group,

which is promoted by his family. He foresaw enormous potential in

the beautiful and green, yet underdeveloped area closes to Hosur town.

Harita is the Sanskrit word for verdant prosperity and he envisioned creating prosperity here

through establishing an auto component industrial network.

Shri Venu Srinivasan, elder son of Shri T S Srinivasan, as a tribute to

his father’s vision, developed Harita into an industrial suburb. The

collaboration between Harita Group and GAG was finalised in 1986,

to incorporate Harita Grammer Limited (HGL) to provide customised

seating solutions, taking into account the difficult Indian road conditions. Commercial

production was started in 1988 and the company soon went public. Since then, the company

introduces a range of new products every year to meet demanding customer’s requirement.

Grammer AG’s (GAG) success story can be traced back to 100 years

(1880), when Mr Willibald Grammer opened a saddlery in Amberg,

Germany. Mr George Grammer, his grandson, expanded the saddlery

to an industrial manufacturing plant. Starting in 1954 with cushions

for tractor seats, by 1964 GAG entered the era of modern seating systems, supplying

suspended seats for agricultural tractors, construction machines, and material handling

equipment. Today, GAG is one of the leading suppliers of seating systems world over. GAG

group comprises 40 facilities in 19 countries around the globe, with group turnover exceeding

1.3 billion-DM.

5

Harita Seating Systems Limited (HSSL) is a complete solution provider for seats

and seating systems for both automotive and non-automotive applications. HSSL

manufactures, driver seats for commercial vehicles, buses, tractors, off-road vehicles, cars,

multi-utility vehicles, two wheeler and three wheeler segments; passenger seats for buses,

cars, multi-utility vehicles and three wheeler segments; and seating systems to the railway and

auditorium segment. The company also offers products for automotive industry through

polyurethane composites Established in 1986; HSSL commenced its commercial production

in 1988. Today HSSL has established itself as the leader in development & manufacture of

innovative seats & seating systems for the commercial vehicles, buses, tractors & off-road

vehicle industry. HSSL recorded turnover of Rs 194 Cr in 2007-08.

During the year 2008-09, the company acquired Polyflex Group of companies. Through this

acquisition, the company has paved the way for entry as a Tier-2 polyurethane foam supplier

to reputed customers like Hanil Lear in Chennai, Tata Johnson Controls and Lear in Pune and

Chennai, and Toyota Boshoku in Bangalore. The foam pads supply will go into the cars of

Hyundai, Tata Motors, Ford, Mahindra Renault and Toyota Kirloskar

6

.

2.2 Organisation profile

2 .2.1 Products and Customers

Fig 2.2.1a products and customers

7

Table 2.2.1 : List of products and major customers

2.2.1 Manufacturing Process

The main processes in the organisation are

1. Polyurethane foaming

2. Powder coating of metal parts

3. Welding

4. Assembly of the seats and seating systems

8

2.2.2 Manufacturing Facilities

Fig 2.2.2: Manufacturing facilities

HSSL has its registered office at Chennai. Infrastructure functions viz.,

Marketing, Personnel, Quality, Finance and R&D operate at the manufacturing location.

HSSL started with tractor and two-wheeler seats to begin with. Over the years, the new

product development has covered the entire range of automotive seating Systems. With clear

focus on customer service to the western market, HSSL, in 1996, set up its second factory at

Ranjangaon, 60 kilometers from Pune.

.

9

Chennai- Registered office

Unit II Ranjangaon

Land: 53,074 sq.mBuilding 3,582 sq.m

Unit I- Hosur

Land : 88,652 sq.mBuilding 7,175 sq.m

Unit III Jamshedpur- Assembly unit

Unit IV Nalagarh

Land: 12000 sq. mBuilding: 2500 sq. m

Manufacturing facilities at Hosur and Ranjangaon includes

1. Modernized Polyurethane Cushion manufacturing unit.

2. Automated Pre-treatment and Powder coating plant

3. MIG welding shop

4. Mould manufacturing shop

5. Plastic Vacuum forming

6. Assembly cells

2.2 .3 Organizational Structure

Fig 2.2.3. : Organisation structure

2.3 Sales Trend of Organization

10

President

Research &

Development

Manufacturing

QualityPurchase Marketing FinancePersonnel

& TQCBusiness Planning

The Sales trend is shown in the below chart

Fig 2.3 : Sales trend of organisation

The company has planned to exceed Rs 250 Crores sales in the next financial year

2009-2010. The company has added products, technology and closely nurtured culture of Total

Quality Management (TQM) pillared by Policy deployment, Kaizen, TEI, Training and

Standardization. The management focus this year on cost reduction under the circumstances of

stiff competition and price war in the market through alternate material, alternate processes,

and waste elimination and productivity improvement projects and also through stringent cost

control measures.

11

2.4 Milestones

Fig 2.4: Milestones

12

Contin

uous

impr

ovem

ent

Manufacturing systemsACMA – Productivity

award

Quality management systemsQS 9000

Management systems

EFQM – CII EXIM

Environmental managementISO 14001

Quality managementACMA Quality

award

Quality management systems

ISO/TS 16949

Manufacturing systemsACMA manufacturing

excellence

Energy managementEnergy conservation

award

Occupational Health and Safety

OHSAS 18000

Energy managementEnergy conservation

award

Water managementExcellent water efficient

unit

ACMA – Automotive Component Manufacturers Association of IndiaCII – Confederation of Indian Industries

Energy managementEnergy conservation

award

Water Management

1 99 9

2 00 0

2 00 1

2 00 1

2 00 3

2 00 3

2 00 4

2 00 5

2 00 7

2 00 6

1 99 6

2 00 9

2 00 7

2.4.1 Commitment to quality

HSSL is committed to provide safety, comfort and aesthetics by supplying

Quality products at right time, in right quantity and at agreed price. With Total Employee

Involvement (TEI) and through consistent innovative actions, these objectives are sure to be

rewarding realities. Total Employee Involvement is achieved through Suggestion Scheme,

Quality Control Circle, and Supervisory Improvement Team, Cross Functional Teams and

TQM activities.

HSSL Believes in:

- High productivity level through cellular manufacturing and Kaizen

- Quality ownership with the operators

- Close interaction with experts for latest technology assimilation

- High level of plant and machinery utilization through practice of TPM concepts

- Priority to environment, health and safety through practice of 5S, and atmosphere of

greenery

We also believe that the TQM practices have helped us to tide over all adverse situations and

continue to guide us towards achieving excellence in business.

2.4.2 Awards and Recognition

The company has obtained TS 16949 certification in September 2003 and

achieved Commendation for significant achievement in business excellence (EFQM Model)

from CII-Exim Bank in November 2000.

Company won ACMA Quality Award for the year 2001The company has also

obtained ISO 14001 Certification during October 2003 towards environmental performance.

13

3.0 Identified problem

3.1 Introduction

In the present period of recession prevailing in all parts of the world, the company

has to manage all the tough situations and be a leader in the market by concentrating on the

following

Productivity

Quality

Cost

Delivery

Morale &

Waste elimination

Also, Indian Economic Reforming policies demand companies to improve their Quality,

Productivity, Cost, and Delivery requirements continually. Continuous Improvement should be

present in the every aspect of the business, without which the companies cannot survive in the

present competitive market.

Particularly after globalization and liberalization, Indian companies are facing stiff competition

and threat from companies of other Countries.

To achieve the business growth, customer delight becomes the prime focus for which the

above said 6 parameters need to be improved to world class levels.

HSSL is the major source to TVSM and the share of business is 100 %. The supplies are made

on Just –In-Time (JIT) basis every hour.

The customer requirement has been consistently growing every year.

Overall Two wheeler segments in India are growing year to year and recorded a growth of

minimum of 20 % consistently. But the contribution values of the two wheeler seats are very

low. This was the main reason to concentrate in this project.

Based on the projected volumes for the year 2009-10 to the tune of 250 Cr, our company has

formulated the following objectives and guidelines.

Policy Objectives for 2011-12

Achieve sales from Rs 191 to 255 Cr

Achieve profit from 6.2 Cr to 9.0 Cr

Improve quality of the products and achieve 50 PPM rejection levels at customer end.

14

Guidelines for 2011-12

Improve productivity through constant/ continuous re-engineering the manufacturing

processes

Design of Experiment (DOE) for materials cost reduction

Apply value engineering (VE) technique for low contribution products

Explore alternate materials for cost reduction

Implement low cost automation (LCA) projects

New technologies for product and process.

JIT supplies to customers

Flexible Production

Bench marking

Lean manufacturing

3 M elimination

Standardisation

Implement waste elimination projects through TEI

Based on the guideline no. 1 & 2, this project is taken up for implementation.

3.2 Description of the problem

3.2.1Automobile sales trend in segment wise

In the below graph the sales trend in each segment for the last quarter of financial year 2011 is

shown. In that Two Wheeler Seat Production is topping the list with 65.4

15

% of the quantity.

Fig 3.2.1a: Sales details - Segment wise

HSSL has started supplies of two wheeler seats to TVS Motor Company (TVSM),

Fig 3.2.1 b: Demand v/s Capacity

Hosur and Mysore in a big way since March 2000. The business with TVSM has

16

119800

27980

10813 8777404

15421

65.4

80.786.6

91.4 91.6100.0

0

20000

40000

60000

80000

100000

120000

140000

TW LCV Tractor BPS Car Others

Segments

Qu

anti

ty

0

20

40

60

80

100

120

% C

um

been consistently growing since then from 2,700 seats per day in the year 2000 – 01 o 5,000 up

to 2007-08. The projected volume for 2011-12 is 8000 seats per day.

At present, with the increasing trend of the production volume, the contribution of the two

wheeler seats are low due to the increasing prices of the raw materials. Various proposals have

been made to reduce the cost of the seats by using value engineering techniques and usage of

alternate materials in line with our policy objectives and strategies.

3.2.2 Two wheeler sales trend in model wise

The chart below shows the product wise sales trend of the two wheeler seats.

This chart clearly shows the product wise volume of the two wheeler seats / month.

TW Sales details

16243

14664

9634

49924400

38163097

19921200 960 482 56 24

19010

43.8

23.6

100.0100.099.999.398.196.694.190.3

85.680.1

73.9

62.0

0

5000

10000

15000

20000

Model

Qu

an

tity

0.0

20.0

40.0

60.0

80.0

100.0

120.0

% C

um

Fig 3.2.2.a: Two wheeler sales details – Model wise

The objective of this project is to develop the optimal method in the material composition of

Two wheeler seat assembly using design of experiments which reduce the material cost by 1 -

3 % and improve the contribution value from 20% to 22%.

17

3.3 IMPORTANCE OF THE PROJECT

Fig 3.3. a: Contribution of Running products

Our customer TVS Motor confirmed their production ramping up plan during the First

quarter of 2011 – 12. TVSM has demanded for the cost reduction of the products

Due to the increase in the quantity of production also. We have drawn a bar chart showing the

existing and planned contribution of 4 running products as per the policy matrix.

From the above graph it is clear that we have to bring down the material cost / manufacturing

cost of the products like Star Sport, Star city and XL - HD

3.3.1 Reason for selecting Star Sport model :

18

A comparative study has been done based on the weight of the cushions running

in the Two Wheeler Foaming Line. Based on the study, we have prepared a chart with the

weight of the components have found that Star Sport model was contributing around 25 %

of the total chemical consumption. Taking this for improvement will contribute in high cost

benefits.

Fig.3.3.1.a –Chemical Consumption – Product wise

We have studied the foam production process of the Star Sport cushions and in order to

reduce the cost of the end product, we have arrived at reducing the weight of the cushions.

This can be done by adopting DOE process in cushion manufacturing using different

chemical composition and bring down the weight by 10 % without affecting the property and

hardness of the cushions.

In order to eliminate the above, we have worked out using DOE techniques to

optimal method in foaming process by changing different chemical consumption. From the

above chart, we have taken Star Sport Seats which tops with the high ratio of 25 %.

From the above table it is very much relevant that Star Sport model consumes more

chemical monthly, hence we concluded that DOE in the said model will give some cost

benefit. This triggered us to go for an idea simulation

3.3.2 Idea Simulator – Star Sport Cushion

19

To optimize the weight of the PU Foam, the company has adopted a technique called

Idea Simulator.

Table 3.1. Idea Simulator for Star Sport foam

20

Based on the discussion held by various department heads for idea simulators it gave us a

positive approach to look for alternate ideas. In the case of Star Sport model, we are optimise

the weight of the PU Foam triggered a good potential for cost benefit as well as customer

complaint elimination.

Taking into account of idea simulation the Star Sport foam hinted a good potential of

material removal without disturbing the basic functionalities benefiting the organization cost

wise.

4. REVIEW OF LITERATURE

4.1 Design of Experiments

In order to benefit the organization by DOE where the problem is dealt with the

following techniques to eliminate the seat rejection; the techniques will definitely show a

positive trend in PPM as well as rejections. Overall the objective of the organization is taken

care in all aspects in terms of delivery, quality and cost.

DOE is a structured, organized method for determine the relationship between factors

(X) affecting a process and the output of that process (Y) while using minimum number of

experimental runs.

Types of DOE

1. Factorial Experiment Design

a. Full Factorial

b. Half/one fourth / one eighth Factorial Design

c. Screening Design

2. Taguchi Approach

3. Central Composite Design

During the improvement of products and processes, there are different “knowledge levels”

starting from a scarce knowledge to a deep knowledge.

Relevant literature review

21

Reference: 1

http://www.moresteam.com/toolbox/index.cfm

Introduction

Experimental design can be used at the point of greatest leverage to reduce

design costs by speeding up the design process, reducing late engineering

design changes, and reducing product material and labor complexity.

Designed Experiments are also powerful tools to achieve manufacturing cost

savings by minimizing process variation and reducing rework, scrap, and the

need for inspection.

This Toolbox module includes a general overview of Experimental Design,

instructions and templates for conducting simple experiments, and links and

other resources to assist you in conducting more complex experiments. A

glossary of terms is also available at any time through the Help function, and

we recommend that you read through it to familiarize yourself with any

unfamiliar terms.

Preparation

If you do not have a general knowledge of statistics, review the Histogram, A

class main link heft"http://www.moresteam.com/toolbox/t404.cfm "Statistical

process Control, and Regression and Correlation Analysis modules of the

Toolbox prior to working with this module.

Although you can use the MoreSteam.com DOE spreadsheet templates to

analyze several experimental designs using Excel or lotus, you will need

statistical analysis software to go beyond these basic experiment design

templates. Several free packages can be downloaded through the

MoreSteam.com Statistical software module of the Toolbox. In addition,

the book DOE Simplified, by Anderson and Whitcomb, homes with a sample

of excellent DOE software that will work for 180 days after installation.

Purpose

Designed experiments have many potential uses in improving processes and products, including:

22

Comparing alternatives. In the case of our cake-baking example, we might want to

compare the results from two different types of flour. If it turned out that the flour

from different vendors was not significant, we could select the lowest-cost vendor. If

flour were significant, then we could select the best flour. The experiment(s) should

allow us to make an informed decision that evaluates both quality and cost.

Identifying the Significant Inputs (Factors) Affecting an Output (Response) -

separating the vital few from the trivial many. We might ask a question: "What are the

significant factors beyond flour, eggs, sugar and baking?"

Achieving an Optimal process Output (Response). "What are the necessary factors,

and that are the levels of those factors, to achieve the exact taste and consistency of

Mom's chocolate cake?

Reducing variability. "Can the recipe be changed so it is more likely to always come

out the same?"

Minimizing, maximizing, or Targeting an Output (Response). "How can the cake be

made as moist as possible without disintegrating?"

Improving process or product "Robustness" - fitness for use under varying conditions.

"Can the factors and their levels (recipe) be modified so the cake will come out nearly

the same no matter what type of oven is used?"

Experiment Design Guidelines

The Design of an experiment addresses the questions outlined above by stipulating the

following:

The factors to be tested.

23

The levels of those factors.

The structure and layout of experimental runs, or conditions.

The flow chart below Figure illustrates the experiment design process:

Factor:

Anything that contributes causally to a response; "a number of parameters

determining the outcome”. Also called independent variables.

Response:

The output of a process. Also called dependent variables.

Level:

Optimal no. of data points in which experiments should be conducted to

correctly conclude the result; a position on a scale of intensity or amount or quality.

24

Reference : II

http://www.ee.iitb.ac.in/~apte/CV_PRA_TAGUCHI_INTRO.htm

TAGUCHI Method:

    Dr. Taguchi of Nippon Telephones and Telegraph Company, Japan has developed a method

based on “ORTHOGONAL ARRAY” experiments which gives much educed “variance” for

the experiment with “optimum settings” of control parameters. Thus the marriage of Design

of Experiments with optimization of control parameters to obtain BEST results is achieved in

the Taguchi Method. Orthogonal Arrays" (OA) provide a set of well balanced (minimum)

experiments and Taguchi's Signal-to-Noise ratios (S/N), which are log functions of desired

output, serve as objective functions for optimization, help in data analysis and prediction of

optimum results.

Taguchi Method treats optimization problems in two categories,

  1.STATIC PROBLEMS:

Generally, a process to be optimized has several control factors which directly decide the

target or desired value of the output. The optimization then involves determining the best

control factor levels of that the output is at the target value. Such a problem is called as a

"STATIC PROBLEM".

This is best explained using a P-Diagram which is shown below ("P" stands for Process or

Product). Noise is shown to be present in the process should have no effect on the output!

This is the primary aim of the taguchi experiments - to minimize variations in output even

though noise is present in the process. The process is then said to have become ROBUST.  

25

2. DYNAMIC PROBLEMS

If the product to be optimized has a signal input that directly decides the output, the

optimization involves determining the best control factor levels so that the "input signal /

output" ratio is closest to the desired relationship. Such a problem is called as a "DYNAMIC

PROBLEM".

  This is best explained by a P-Diagram which is shown below. Again, the primary aim of the

Taguchi experiments - to minimize variations in output even though noise is present in the

process- is achieved by getting improved linearity in the input/output relationship.

26

STEPS   IN   TAGUCHI   METHODOLOGY :

STEP-1: IDENTIFY THE MAIN FUNCTION, SIDE EFFECTS, AND FAILURE MODE

STEP-2: IDENTIFY THE NOISE FACTORS, TESTING CONDITIONS, AND QUALITY CHARACTERISTICS

STEP-3: IDENTIFY THE OBJECTIVE FUNCTION TO BE OPTIMIZED

STEP-4: IDENTIFY THE CONTROL FACTORS AND THEIR LEVELS

STEP-5: SELECT THE ORTHOGONAL ARRAY MATRIX EXPERIMENT

STEP-6: CONDUCT THE MATRIX EXPERIMENT

STEP-7: ANALYZE THE DATA, PREDICT THE OPTIMUM LEVELS AND PERFORMANCE

STEP-8: PERFORM THE VERIFICATION EXPERIMENT AND  PLAN  THE  FUTURE  ACTION

4.2 DOE process map :

27

Define the Objective

Choose Measures of performance

(Output Variables)

Identify Possible Factors

(Control Variables)

Design Programme of Experiments

Collect Data

Analyze and Interpret Results

Verify Results

Return to 3 as necessary

BrainstormingCause and Effect

Diagram

Full Factorial

Fractional Factorial

ScreeningTaguchi

GraphsRegressi

onANOVA

ReplicationRandomization

Repetition

88

77

66

55

22

33

44

Table 4. 1: – Design of Experiments Approach

4.3 METHODLOGY

In this project, the following methodologies are adopted to find the optimal

method of two –wheeler seat assembly (Foam cushion area) using Design of Experiment.

Study of the current process

Usage of Design of Experiment Techniques

Adaptation of DOE concept

Literature survey on DOE process in change process

Prepare questionnaire to understand the issues involved in the change process.

Implementation and Standardization

Trail running with the change process to measure the outcomes

Collection of data by experiments

Analyze the data collected thro quality tools

Conclusion

28

Approaches No of variables DOE

Screening

(Scarce know-how of the process and many variables)

> 7

Fractional Factorial Low Resolution (III)

Characterization

(Reduced number of variables and their interactions)

4 - 7

Full Factorial or Fraction Factorial with High Resolution (IV or V)

2 - 4

Optimization

(Deep investigation for few variables and their interactions)

Full Factorial

Leve

l of K

now

ledge

Leve

l of K

now

ledge

5.0 DATA COLLECTION AND ANALYSIS

5.1 TYPE OF DATA NEEDED

In order to achieve cost reduction by DOE in the two wheeler seat to improve the contribution,

we have collected the following data.

Customer complaints pertaining to Star Sport

In-house rejection trend of Star Sport

Current process parameters of Star sport cushion manufacturing.

Quality standards for cushion manufacturing.

5.1.1 Customer complaints

A detailed history of the past year trend has been taken on the seat rejection

by customer due to High Hardness. On an average there were rejections around 130

Nos/annum. For the year 2009-10 the average rejections per month was12 nos.

The below data are collected based on the customer complaint from April

2009 to March 2010.

Table .5.1.1: Customer Complaints – High hardness

Apr

'09

May

'09

Jun

'09

Jul

'09

Aug

'09

Sep

'09

Oct

'09

Nov

'09

Dec

'09

Jan

'10

Feb

'10

Mar

'10

12 22 15 9 16 18 20 25 18 10 11 13

29

Fig 5.1.1.a: Customer complaint due to Seat High Hardness–Year wise

Fig 5.1.1.b.: Customer complaint due to Seat High Hardness– Month wise

Fish Bone Diagram for High hardness

30

Past years trend

200

160

125

0

50

100

150

200

250

07 - 08 08 - 09 09-10

Year

Qu

an

tity

Monthwise trend 2009-10

12

22

15

9

1618

20

25

18

10 11

13

0

5

10

15

20

25

30

Apr '09 May'09

jun '09 Jul '09 Aug'09

Sep'09

Oct '09 Nov'09

Dec'09

Jan'10

Feb'10

Mar'10

Month

Qu

an

tity

There are many various reasons for High Hardness in foaming process. Brain

storming session conducted with employees and the reasons are correlated each other

using Fish Bone Diagram.

Fig 5.1.1.c: Cause and effect diagram

Criticality of the problem (High Hardness)

The problem of Seat High Hardness is having an average trend of 180 nos

getting rejected annually. There are certain affects to the Quality rating, Delivery commitment

causing line stoppers at the customer’s end. An increased trend of PPM is always alarming to

the company’s growth perspective.

The rejection value of seats getting rejected :

Cost of each seat : 380

No. of seats rejected /year: 180

Total rejection value : Rs.68400

Intangible cost : Rs.5000

Total cost : Rs.73400.

31

Machine setting

improper Input Chemical variation

Operator negligence

Untrained operator

Importance not known

Input Chemical problem

Improper Chemical Mixing Ratio No proper

traceability No proper pouring method

MAN MACHINE

METHODMATERIAL

High Hardness

Effect: 100%

Hence to eliminate seats getting rejected it is always necessary to go for a

DOE project, thus giving a potential for benefiting the organization

5.1.2.In-house rejections

Cushions are checked for its properties like hardness, profile, shape and

other surface defects. The parameter hardness predominantly contributes towards the seat’s

comfort level.

Testing of hardness is done as per IS 7888 for 4 wheeler cushions and JIS

6401 for Two wheeler cushions. Hardness testing will be carried out regularly to ensure

conformance to the specification.

If the manufactured cushions are not meet the quality standards it is

booked as In house rejection and moved to scrap area.

The below In house rejection data which is taken from SAP from April 2009 to March

2010.

Table 5.1.2: In house Rejections – High hardness

Apr

'09

May

'09

Jun

'09

Jul

'09

Aug

'09

Sep

'09

Oct

'09

Nov

'09

Dec

'09

Jan

'10

Feb

'10

Mar

'10

8 12 6 9 15 11 16 9 13 10 8 13

32

Past years trend

220

180

155

0

50

100

150

200

250

07 - 08 08 - 09 09-10

Year

Qu

anti

ty

Fig 5.1.2.a.: In House Rejections–Year wise

Fig 5.1.2.b: In house rejections due to Seat High Hardness– Month wise

5 .2. SOURCE OF DATA

Various sources for the types of data identified above are

a. Process flow diagrams can be collected from the Cushion Production on the basis of the

Process layout.

b. Operation standard formats can be received from the Plant Engineering

c. Customer complaint and in-house rejection details from our QAD.

d. Chemical consumption and production volume details from our SAP system

33

Monthwise trend 2009-10

8

12

6

9

15

11

16

9

13

108

13

0

5

10

15

20

Apr'09

May'09

jun'09

Jul'09

Aug'09

Sep'09

Oct'09

Nov'09

Dec'09

Jan'10

Feb'10

Mar'10

Month

Qu

an

tity

e. Test report from Quality Testing Department

5.3 DETAILS OF DATA COLLECTED

Following are the collection of data for

1. Customer complaints

2. In House rejections

3. Production Quantity

This Production quantity data has been collected from our Foaming Production

department from April 2009 to March 2010.

Table 5.3.1 : Star Sport Cushion Production quantity

Apr

'09

May

'09

Jun

'09

Jul

'09

Aug

'09

Sep

'09

Oct

'09

Nov

'09

Dec

'09

Jan

'10

Feb

'10

Mar

'10

12571 9695 15574 16138 15368 20524 19724 16226 9451 8620 12226 16600

In addition the following data also collected for supporting the analysis.

Process flow diagrams of the Hennecke PU Foaming Machine.

Operation standards for the Star sport Foaming Machine.

6. PU Foaming Process

The term "POLYURETHANE" is used to describe any polymer that has been chain extended

by reaction with di or poly-isocyanate. In other words "POLYURETHANES" are polymers

formed by the polyaddition of polyfunctional isocyanates with compounds containing at least

two hydroxyl groups.

The term polyurethane is derived from the "URETHANE" group that is predominantly

formed in the reaction. A urethane group is formed by the chemical reaction between an

34

alcohol and an isocyanate. The isocyanate group (-NCO) can react with any compound

containing 'active' hydrogen atoms. (Active hydrogen atoms are those which react with a

Grignard's reagent, generally methyl magnesium iodide to give methane.)

The typical reaction that depicts the formation of polyurethane’s (PU) is given below:

Polyol + water and/or Polyisocyanates or POLY

Blowing agent + catalyst(s) Diisocyanates URETHANE

FOAM

The two wheeler cushion production unit consists of the following machines and equipment

1. High pressure reaction moulding machine – 1 No

2. Linear carousel carrying 14 mould stations

3. 14 individual moulds each with 2 cavity

4. Injection head fitted on a rotary arm

1. High pressure reaction moulding machine:

This high-pressure reaction moulding machine is of “Hennecke” make from imported

from Germany. The machine consists of storage tanks to hold Polyol and Isocyanate in a

maintained temperature of 21 – 25 degrees centigrade, the control unit, computer controlled

programmable unit, metering units to control the quantity of both the chemicals

35

Fig 6.1 High pressure reaction moulding machine

2. Linear carousel

The linear carousel is nothing but a closed loop telescopic conveyor chain

fitted with a caterpillar drive and used to move the mould carrying fixtures. The movement &

the speed of the conveyor are controlled through a control panel and an automated lubricator

unit ensures the smooth movement of the conveyor. There are 14 moulds carrying stations or

otherwise called as Mould Fixtures (MF), individually operated through hydraulic power

pack. The mould carrying stations are locked with the towveyor chain conveyor through

towing pins. The power supply is given the MFs through an overhead 4-line bus bar.

36

High pressure reaction moulding machine

Fig 6.2: Linear carrousel with mould fixtures

3.Moulds

Moulds are used to produce PU cushions. The moulds are CNC machined to obtain

the contour of the cushion and made up of Aluminium. Different varieties of mould cavities

are used for various products. We have about 20 varieties of two wheeler moulds.

Fig 6.3: Aluminium mould cavity

There are 14 moulds with each with twin cavity are mounted in the mould carrying

stations. Each mould consists of top and bottom cavity. The top cavity is mounted in the top

frame of the MF by means of T bolts and the bottom cavity is fixed to the base frame of the

MF by means of conical locators. Hot water connection is given to the moulds to maintain the

mould temperature always between 55 – 60 degrees centigrade.

4.Injection head and the rotary arm.

The injection head is the important part of the machine where is both Polyol

and Isocyanate are mixed thoroughly inside the chamber at a high pressure of 160 – 180 bar

and the laminar flow is created inside for homogenous mixing through the injection nozzle.

Then the homogenous mixture is injected into the mould. The rotary arm consists of a pillar

37

support, rotary base, pivoted arm with a counter weight and the moving arm where the mixing

head is mounted. The movement of the mixing head is achieved by means of a robot.

Each type of cushion requires certain type of machine setting depend on the size, hardness,

weight and other requirements. These settings are stored in the PLC of the machine .

RFID will activate the signal to the foaming machine thro the sensors, The machine has the

input details and gives the signal to the control panel of the Robot , Each individual moulds

having individual program stored in the control panel of the machine. The Robot gets the

input details from the Control panel of the machine and pouring of the chemical in the mould

cavity.

Cushions are checked for its properties like hardness, profile, shape and other surface defects.

The parameter hardness predominantly contributes towards the seat’s comfort level.

Testing of hardness is done as per IS 7888 for 4 wheeler cushions and JIS 6401 for 2 wheeler

cushions. Hardness testing will be carried out regularly to ensure conformance to the

specification.

6.1 Conclusion

Following points are taken care during the data collection.

1. Data collected is done from normal sales taking place in the organization ensuring the

desired range of sales trend is covered.

2. In house rejection trend is formulated from the actual data entered in the in house

software for daily monitoring.

3. Much care has been taken to ensure unbiased data collection during the entire study in

order to achieve reliability.

The collected data has been formatted and are further used for analysis.

7.0 ANALYSIS OF DATA

7.1 CHOICE OF TECHNIQUES

DOE technique is used in this project as where applicable. The tools are selected suitable to

the analysis and study requirements.

Following techniques are used during the course of this project

38

Brainstorming is done to collect ideas.

Cause and effect diagram is used for causal analysis.

Trend charts has been used to formulate Production trend.

DOE techniques used for cost reduction and standardization.

7.1.1 DESIGN OF EXPERIEMENT IN STAR SPORT CUSHIONS

We have taken the present process parameters, specification and observations of the

Star Sport cushions

In order to optimize cost in the Star sport Cushion, we have identified the the index of

potential to achieve maximum benefits. The following sub parts are recommended.

1. Reduction in weight of the base chemical in Star Sport Cushion by DOE

We have taken the present process parameters, specification and observations of the Star Sport

cushions.

7.1.1 Selection of Factors for DOE

As a first step of DOE, we have analysed on the process parameters with respect to the local

control factors and the factors that can be taken for DOE.

Table 7.1.1– Selection of Factors for DOE – Star Sport Cushion

39

Inj time : 3.55 Seconds

Polyol qty/ Sec : 128 gms

ISO Qty / Sec : 78 gms

Cushion weight : 705 gms

Hardness : 11 - 15 Kgf

Hysterisis : 26 - 28 %

Supplier : Dow Chemicals

ISO : NE 134

Polyol : NF 755

7.1 Present Process Parameters of Star sport cushion

We have arrived at the different levels of experimental combinations by

varying the injection time and the ISO quantity. The combinations are shown in the below

table.

Factors

1. Injection Time2. ISO Qty

40

Process Parameters

1. Injection Time

2. ISO Qty

3. Injection Pressure ISO/Polyol

4. Mould temperature

5. Release agent application

6. Mould

7. Component Temperature

Factors for DOE

-

-

-

-

-

Local control

-

-

-

Levels

3.5, 3.45, 3.35, 3.25, 3.15 secs78, 80, 82, 84, 86 Gms

We have used the ANOVA table to find the significance between the different setting and the

cushion hardness.

We have compared the average response of the following parameters

1. Weight

2. Hardness and

3. Hysterisis

The ability of Flexible Polyurethane Foam (FPF) to maintain original

characteristics after flexing. Indentation Force Deflection (IFD) is generally measured as

the force in pounds required to compress a 50 sq inch circular indenter tool into four inch

thick sample. Common IFD values are general at 25 and 65% of the initial height.

41

Table 7.1.1.a – Experimental Combination of

injection time & ISO quantity

7.1.3 Experimental Combination - Full Factorial

3.15 x 78 3.25 x 78 3.35 x 78 3.45 x 78 3.55 x 78

3.15 x 80 3.25 x 80 3.35 x 80 3.45 x 80 3.55 x 80

3.15 x 82 3.25 x 82 3.35 x 82 3.45 x 82 3.55 x 82

3.15 x 84 3.25 x 84 3.35 x 84 3.45 x 84 3.55 x 84

3.15 x 86 3.25 x 86 3.35 x 86 3.45 x 86 3.55 x 86

Cushion hardness is checked using the Hardness Test as per the Quality Standard

of Japanese Industrial Standards (JIS 6401). As per the Specifications the hardness should

be 11 – 15 kgf.

Table 7.1.1.b – ANOVA Table

42

ANOVASource of Variation SS df MS F F crit

Injection time 94.444 4 23.611 122.974

3.006917ISO Qty

80.244 4 20.061 104.484

3.006917Error 3.072 16 0.192

Total 177.76 24

Both Injection time & ISO Qty are significant for Hardness. (F value > F critical)

ISO Qty78 80 82 84 86

3.15 8.8 9.2 10.8 12.4 14.8

3.25 10.2 10.8 11.2 12.7 15.2

3.35 11.4 12.1 12.7 14.8 16.2

3.45 14.8 15.7 16.2 17.9 18.5

3.55 12.5 13.7 14.2 15.8 17.9

Inje

ctio

n

Tim

e in

se

cs

Figure 7.1a – Average Response of Weight – Star Sport Cushion

Figure 7.1b – Average Response of Hardness – Star Sport Cushion

43

Average Response on Weight

705

641

661

669 670

708

600

620

640

660

680

700

720

3.15 x 84 3.25 x 84 3.35 x 80 3.35 x 82 3.55 x 78 3.55 x 80

Trial Combination

Wei

ght i

n gm

sExisting

LCL

UCL

Average Response on Hardness

13.713.1

12.712.5 12.4

12.1

8

11

14

17

3.45x 86

3.45x 84

3.55x 86

3.35x 86

3.45x 82

3.55x 84

3.45x 80

3.25x 86

3.15x 86

3.35x 84

3.45x 78

3.55x 82

3.55x 80

3.35x 82

3.25x 84

3.55x 78

3.15x 84

3.35x 80

3.35x 78

3.25x 82

3.15x 82

3.25x 80

3.25x 78

3.15x 80

3.15x 78

Trial combination

Har

dn

ess

Figure 7.1.3c– Average Response of Hysterisis

Figure 7.1.c – Average Response of Hysterisis – Star Sport Cushion

7 .1.5. Trial Result

After the following trials, we found that the Hardness, hysterisis property

which is the main parameters was satisfied at the weight of 670 Gms. So, we have set the ISO

quantity at 82 Gms / sec and Injection timing at 3.35 and done the process capability and

found the hardness was within specification.

By the application of DOE process we found the optimum method of

Injection time 3.35 sec with the chemical combination of ISO quantity of 82 Gms/sec

By implementation of the project, we were able to reduce the weight of the

Cushion by 5 %

44

Average response on Hysterisis

30.4

28.527.127.2

29.8

24

27

30

3.15 x 84 3.25 x 84 3.35 x 80 3.35 x 82 3.55 x 78 3.55 x 80

Trial Combination

Hys

teri

sis

in %

Existing process

parameter

Parameters identified

during experiments

7.1.6 Testing and Proving

Figure 7.0h – Methods of Testing

Figure 7.1.4– Testing and Proving

45

7.1.7 Test Report

46

Table 7.1.7 – Test Report – Star Sport Cushion

7.2. Standardisation

List of activities carried out towards standardisation of this Project.

Drawing modification through Engineering Change Note ( ECN )

Bill of Material ( BOM ) modification

Intimation to production and updation of the Operation standards

Norms updated in the system

Process parameters updated

Updation of the control plan

Training imparted to all individuals.

Approval from customer

8.Results and Benefits

During 2009-10 the contribution of the two wheeler seat on the overall cost was

around 16 – 20 %. Projected volumes for the year 2012-13, are 9,600 seats per day, we

have planned to improve the contribution of the Two Wheeler Seats and also improve the

profitability of our company as per the policy plan.

47

To meet the above demand, following activities were implemented.

1. Design of Experiments in Star Sport Seat.

Figure 8.0– Plan Vs Actual

After standardizing the above activities in the regular production, we could achieve the

following benefits

A. Achieved cost saving of Rs 5.12 Lakhs per annum (Break up details given below)

Cost Savings through DOE in Star Sport Seat -Rs. 5.12.00 Lakhs

8.1 Improvements planned in the year 2011 – 12

This improvement has been planned to be horizontally deployed to all similar products. The

target for implementation is during MAY ’11.

48

5 % Reduction in weight

Star Sport Cushion Weight

705

670675

600

650

700

750

Actual Plan Achieved

Wei

gh

t in

gm

s

9 Conclusions

9.1 SUMMARY OF FINDINGS

This project work has given very good information on the usage of the major tools

like Design of Experiment, ANOVA, Idea simulators etc., It has also provided me knowledge

on the PU Foaming Process.

9.2 GAINS OF THE PROJECT

This project yielded gains in terms cost, quality, delivery, time, etc., which we

have discussed in detail in section 8. Apart from the above, this project also provided an

opportunity to understand the PU Foaming Process and also implementation of projects in

practical at field and overcoming the difficulties and consequences faced. Benefit and

improvement gained out of this project has also motivated to improve my skills in problem

solving techniques.

9.3 LIMITATIONS OF STUDY

These techniques used can be horizontally deployed to other products. We could

not go about in taking trial of the four cavity mould, due to a short time span, the increased

investment and the chemical properties.

9.4 SCOPE OF FURTHER WORK

Similar study can be extended to the other products in the organization where

there is a real need of the cost optimization

49

10. CONCLUSION

This project has given me immense confidence to handle similar projects in the other

areas.

It has enhanced my knowledge on usage of Design of Experiment.

This project has benefited the organization in terms of cost reduction to the tune of Rs. 5.12

lakhs / annum.

“Insect eye view” to any problem or an activity always improves the performance and

utilization.

Tools followed like ANOVA, idea simulators has helped to detect early failures of the system

and also provided opportunity to focus on accident prevention. This also helped in team

building by involving many people in the organization to use those tools.

50

11. REFERENCES

1. Design of Experiments – Taguchi

2. Design and Analysis of Experiments – Douglas C. Montgomery, Third Edition

3. G. Woods, 1990, “The ICI Polyurethanes book, 2nd Edition: ICI Polyurethanes,

Everberg, Belgium jointly published with John Wiley & Sons.

4. Value Engineering for Cost Reduction and Product Improvement – M.S. Vittal;

Systems Consultancy Service, Bangalore.

5. Getting more at Less Cost-The Value Engineering Way-G. Jagannathan ;

6. Tata Mc Graw Hill Publishing Co. Ltd. New Delhi.

51

ACKNOWLEDGEMENT

I sincerely thank Mr.P.SHANMUGAVEL, Manager-Manufacturing- Harita Seating

Systems Limited for giving me an opportunity to do a project in this organization and

valuable advice and continuous guidance in completing the project.

I express my immense gratitude to Mr.M.K.KANNAN, General Manager–

Manufacturing, for permitting me with free hand to complete the project. I wish to convey

my heartfelt appreciation to those countless friends who gave me moral support and

encouragement.

I also wish to thank all my colleagues in my department for their valuable inputs during the

project.

52