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Name: - Vivekanand PAndey

Roll No:-PGEMP40/A/30

Question: -Select a Business Issue in your Domain/ Organization and explain the application of the Problem

Solving/ Six Sigma tools

Introduction about Six Sigma(6)

Six Sigmais abusiness management strategy,originally developed byMotorola,USA in 1986. Six sigma became well

known afterJack Welch made it a central focus of his business strategy at General Electric in 1995, and today it is widely

used in many sectors of industry.

Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and

minimizingvariability inmanufacturing andbusinessprocesses.It uses a set ofquality management methods, including

statistical methods,and creates a special infrastructure of people within the organization ("Black Belts", "Green Belts",

etc.) who are expewelds in these methods. Each Six Sigma project carried out within an organization follows a defined

sequence of steps and has quantified financial targets (cost reduction and/or profit increase).

The term Six Sigmaoriginated from terminology associated with manufacturing, specifically terms associated with

statistical modeling of manufacturingprocesses.The maturity of a manufacturing process can be described by a sigma

rating indicating its yield, or the percentage of defect-free products it creates. A six sigma process is one in which

99.99966% of the products manufactured are statistically expected to be free of defects (3.4 defects per million). Motorola

set a goal of "six sigma" for all of its manufacturing operations, and this goal became a byword for the management and

engineering practices used to achieve it.

The term "Six Sigma" comes from a field of statistics known asprocess capability studies. Originally, it referred to the

ability of manufacturing processes to produce a very high propoweldion of output within specification. Processes that

operate with "six sigma quality" over the showeld term are assumed to produce long-term defect levels below 3.4defects

per million oppoweldunities (DPMO).Six Sigma's implicit goal is to improve all processes to that level of quality or better.

Method used in Six Sigma

DMAIC is used for projects aimed at improving an existing business process. DMAIC is pronounced as "duh-may-

ick".

Back Ground:-

Tilt cab fabrication line is a new body shop which is meant for assembly of tilt cabs by using MAG(metal active gas) or CO2

welding and spot welding machines. The work is being carried out by a total of 6 contractors under direct supervision ofTATA Motors. This shop is used to manufacture all the tilt cabs used in various chassis of trucks.

Define the problem:-

In the month of July 11, the weld defects (in the cabins) percentage shot up to 5% which was very high against our target

of 2%.The DPI showed a downward trend, dipping to almost 71.08% in the month of July11against our target of 90% &

above. Hence, a need was felt to curb the situation & a brain storming session was conducted get desired results. Some of

the following hurdles were targeted to come out of this situation.

1) Improper supply of CO2 gas to the welding torch tip

2) Non uniform gaps in the overlapping sheet metal pieces

3) Variation in the supply current

http://en.wikipedia.org/wiki/Strategic_managementhttp://en.wikipedia.org/wiki/Motorolahttp://en.wikipedia.org/wiki/Jack_Welchhttp://en.wikipedia.org/wiki/Statistical_dispersionhttp://en.wikipedia.org/wiki/Manufacturinghttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Quality_managementhttp://en.wikipedia.org/wiki/Statisticshttp://en.wikipedia.org/wiki/Process_capabilityhttp://en.wikipedia.org/wiki/Process_capabilityhttp://en.wikipedia.org/wiki/Defects_per_million_opportunitieshttp://en.wikipedia.org/wiki/Defects_per_million_opportunitieshttp://en.wikipedia.org/wiki/Six_Sigma#cite_note-ssdefn-9http://en.wikipedia.org/wiki/Six_Sigma#cite_note-ssdefn-9http://en.wikipedia.org/wiki/Defects_per_million_opportunitieshttp://en.wikipedia.org/wiki/Defects_per_million_opportunitieshttp://en.wikipedia.org/wiki/Process_capabilityhttp://en.wikipedia.org/wiki/Process_capabilityhttp://en.wikipedia.org/wiki/Statisticshttp://en.wikipedia.org/wiki/Quality_managementhttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Manufacturinghttp://en.wikipedia.org/wiki/Statistical_dispersionhttp://en.wikipedia.org/wiki/Jack_Welchhttp://en.wikipedia.org/wiki/Motorolahttp://en.wikipedia.org/wiki/Strategic_management

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4) Supply voltage fluctuation issues

5) Welding electrode flux material issue

All the above points, except for point no. 5 (welding electrode flux material),were not in direct control of Tilt Cab shop.

Hence, we had taken up the challenge of Zero Defectsalong with Zero Repoweldable Accident for all the jobs in TILT

CAB SHOP. In the earlier days there were lots of defects in some of the cabins manufactured in TILT CAB SHOP due to

which the cabinss delivery got delayed .

And hence in the month of August 2011 a team was formed as SDT(self directed team) on Zero Defects. I was a paweld

of the team along with members from other functional areas like QA, Production, Production Engg and Maintenance.

Objective (Business need):-

The main objective of our Team was to achieve absolutely zero defects in the welded seams in TILT CAB SHOP irrespective

of welding process, material, Thickness, Welder skill etc.

Measure & Analyze:-

In the very first meeting, we have decided the action plan for moving towards our goal of Zero Defects in welding. Very firstthings we have decided that, even though the goal which we have set is very difficult but, it can be achieved by the co-

ordination & effowelds of all. The following action plan was made.

1. Spread message @ zero defectsin the respective Contractor groups of the Team members.

2. Past Data collection of WELD Defects.

3. Online data entry format for WELD status uploaded in PLM server.

4. Weekly/monthly WELD defect analysis (Seam wise, welding process wise, Welder wise, Contractor wise).

5. Based on detailed analysis, interaction to be done for improvement with concern welder, contractor, and

supervisor in every month.

6. Standard checklist made for defect prevention.

7. In case of defect, it should attempt to clear in 2nd

iteration.

In Aug 2011, the total no of WELD defects were 85 out of 1612 Nos (i.e. spot wise defect %=5.3%).After the drive the

defect % reduction observed to some extent, But the No. of defect spots were showing the increasing trend. During this

process of controlling defects, we came across a Book Quality is free by Philip B. Crosby.

Improve:-

Methodology given in the book is studied by all the team .Some of the main take away from the book is as follows.

Belief on the drive.

Feedback (before, During, After welding).

The basic reason of any defect given in the book is lack of Knowledge & Attention (Gyan aur Dhyan).

We took that as a Mantrafor our drive & started working according to it. For knowledge we started training sessions on

welding processes & weld defects, their causes & preventions for all the welders in consultation with Welding engineers.

Also pre test & post test carried out to enhance knowledge level. Some more actions taken were as follows.

1. Every welder to maintain his own pocket diary to record details of the seams welded by him. (Date, Project no,

Seam no, material, thk, welding process etc.)

2. Daily interaction with welders regarding the status of WELD results of the seams welded by them.

3. Weekly problem sharing sessions for the welders who have produced defects.

4. Brain storming session conducted for all the workmen (including welders, Fitters, Grinders, and Supervisors etc.)

to know the reasons for defects (Slag, Porosity, Lack of fusion etc).

During this brain storming session we came across more than 100 reasons which were directly or indirectly related to

defects in weld seams. Following action taken after the feedback of brainstorming session.

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1. Target Zero Defect-message written beside every seam on job by every shop supervisor.

2. Change of electrode brand from one to another.

3. File note circulated & posters displayed for restricting mobile usage at work place.

4. Eye check up camp conducted for all the workmen to check eye sight healthiness.

5. Monthly appreciation of the welders who have produced zero defects.

6. More emphasis given on welding one seam by one welder.

7. Maintaining of depth chaweld for all the seams in which more than one welder is welding.

8. Up dating daily WELD status on the board by every shop supervisor in Tilt Cab shop from Dec 2011.

9. Display of boards containing status of WELD spots welded by welders. (Status of Success & failure in WELD

Spots.)

After 6 months, we first time reached to single digit figure of defect in the month of Dec 2010 (24 defects out of 1538 no of

spots. Spot wise defect % =1.5 %) But some how we were not able to reach to our target of zero defects. There were many

ups & downs in the defect % up to May 2012. Once during shop round the GM of TILT CAB SHOP motivated the team. He

told that we are very close to our target of zero defects, but we have to put our best efforts to achieve the goal of zero

defects.

Control:-

Hence the team decided to work on elimination of the possible reasons of defect by controlling the process & achieve the

Goal of zero defects. First of all we had a meeting in the Tilt Cab shop to decide the final action plan.

All the shop team members will put positive efforts towards achieving the zero defects.

Excuse will not be given by any shop supervisor for the defects, rather than the detail investigation will be carried

out to find the exact root cause of the defect, so that corrective action can be taken in future for eliminating that

cause permanently.

Each & every shop supervisor will check all the parameters before starting of welding, during Welding and after

welding as a parameter of process control.

Talking to welders before issuing weld parameter sheet for any new seam.

In case, more that two welders are required to be put then Depth chart weld to be prepared & maintained for

the respective seams.

Every shop supervisor will visit all the welders working on their respective cabins at least 3 times in a day to

ensure whether they are following the required parameters. Also he will solve their difficulties if any.

The welders are identified from the each contractor to weld the WELD joints. While making the consumable slip, Shop supervisor will personally check whether the welder is having all the

necessary parameters, Check list, Equipments etc.

Results of Execution:-

After a long journey finally we have achieved zero weld defects (Spot wise) in our weld shop. First we have completed 30

Days with out defect, then 50 days. First time in the history of Heavy Engineering we have completed 100 Days with out

defect. Further we have set a bench mark of 140 days without defects as of now. We have celebrated this grand event by

distributing chocolates to all the workmen who had a big contribution to achieve this grand success.

This achievement of Zero Defects has led to the following concrete advantages.

Tangible benefits

a) Reduction of cost of weld defect to Zero.

b) Reduction of Cycle time for manufacture (25% reduction in Cycle time.)c) Cycle time of one weld defect (i.e. 2.5 days) brought to Zero.

Intangible benefits

2) It has resulted in elimination of unwanted job schedule elongation because of defects.

3) Involvement of a number of agencies (like WE, QC, NDT, TPI etc) for defects got reduced to zero & this inturn helpedus to be on Schedule.

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4) This programme has resulted in Cultural (Mindset) change in thinking for workmen/Contractors that it is possible to

achieve zero defect which otherwise was thought one or two defects are OK.

5) It has brought good/healthy competition among welders/contractors & teams as well.

6) Quality & Productivity improved drastically since job is ready for further operation.

7) Subsidiary offshoot of this programme is also

a) Reduction of cost of weld defect.

b) Reduction of Cycle time for manufacture.

c) Uncertainties accounting in schedule/adding contingencies in schedule for defect welding is eliminated.