SUMMER TRAINING REPORT ON

MANUFACTURING PROCESS

OF DISTRIBUTION TRANSFORMERS

AT

CROMPTON GREAVES Ltd. , MALANPUR [M.P]

SUBMITTED TO: - SUBMITTED BY: -

PALASH TIWARI

0928EE091038

BE VII SEM, IPS CTM ,GWALIOR

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Introduction

Crompton Greaves (CG) is the part of the US $3billion Avantha Group, a conglomerate with an impressive global foot print. Since its inception, CG has been synonymous with electricity. In 1875, a Crompton 'dynamo' powered the world's very first electricity-lit house in Colchester, Essex, U.K. CG' s India operations were established in 1937, and since then the company has retained its leadership position in the management and application of electrical energy .Today, Crompton Greaves is India's largest private sector enterprise. It has diversified extensively and is engaged in designing, manufacturing and marketing technologically advanced electrical products and services related to power generation, transmission and distribution, besides executing turnkey projects. The company is customer-centric in its focus and is the single largest source for a wide variety of electrical equipments and products. With several international acquisitions, Crompton Greaves is fast emerging as a first choice global supplier for high quality electrical equipment

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ACKNOWLEDGEMENT It gives me great pleasure to express my deep sense of gratitude to Mr. Darpan Likhar, without whose patient guidance and constant encouragement this study would not have come to its present form. I am sincerely thankful to him for permitting me to work on a topic of special interest to me for study. I owe him a debt of gratitude for constructive criticism from time to time during the course of these investigations .I am also highly grateful to other faculty members for providing all facilities for carrying out this project work. My sincere thanks must go to my family members who showed patience and forbearance during the period of our study

PALASH TIWARI0928EE091038, BE VII SEMIPS COLLAGE OF TECHNOLOGY AND MANAGEMENT2009-2013

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TABLE OF CONTENT

1. INTRODUCTION2. NEED OF PROJECT3. COMPANY PROFILE AND GROUP4. COMPANY PRODUCTS5. ABOUT T2 MALANPUR UNIT6. PRODUCT RANGE7. INTRODUCTION TO TRANSFORMERS8. MANUFACTURING PROCESS9. CONCLUSION

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History

Crompton Greaves goes back to 1878, when Col. R.E.B. Crompton founded R.E.B. Crompton & Company .The company merged with F.A Parkinson in the year 1927 to form Crompton Parkinson Ltd., (CPL).Greaves Cotton and Co (GCC) was appointed as their concessionaire in India. In 1937, CPL established ,it's wholly owned Indian subsidiary viz. Crompton Parkinson Works Ltd., in Bombay, along with a sales organization, Greaves Cotton & Crompton Parkinson Ltd., in collaboration with GCC. In the year 1947,with the dawn of Indian independence, the company was taken over by Lala Karamchand Thapar, an eminent Indian industrialist. Crompton Greaves is headquartered in a self-owned landmark building at Worli, Mumbai .

Today, Crompton Greaves (CG) is part of the US$3 Billion Avantha Group, a conglomerate with an impressive global footprint. Mr. Gautam Thapar, the third generation of Lala Karamchand Thapar, is Chairman & CEO of India's foremost diversified corporation, the Avantha Group. Mr. Sudhir MohanTrehan is the Managing Director of Crompton Greaves Limited since May 2000. He was the recipient of the

Outstanding Chief Executive of the Year Award for 2000-2001, instituted by the Indian Institution of Industrial Engineering, for steps he took towards successfully implementing his vision of making Crompton Greaves a world-class manufacturing company. In addition to above, the Board of Directors includes the renowned names of Dr. O. Goswami, Mr. S. Labroo, Dr. Valentin A H von Massow, Ms. M.Pudumjee, Mr. S.P. Talwar and Mr. S.R. Bayman.5 Major Acquisitions Pauwels Acquisition Crompton Greaves has completed the acquisition of the Belgium-based Pauwels on 13th May 2005.Ganz Acquisition Crompton Greaves have also successfully acquired Hungarian based Ganz (GTV),

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engaged in the manufacture of EHV Transformers, Switchgear, Gas Insulated Switchgear (GIS), Rotating Machines and Contracting businesses and Trans verticum Kft (TV), engaged in the supporting areas of design, erection ,commissioning and commercial activities on 17th October,2006; TV being a subsidiary of GTV .Microsol Acquisition The acquisition of Microsol Holdings Limited (MHL) and its associate companies in May 2007 is yet another significant stride in CG's journey towards positioning itself as a Global T&D Solutions Provider .Sonomatra Acquisition Crompton Greaves concluded an arrangement for the acquisition of Societe Nouvelle de Maintenancede Transformations (Sonomatra) of France in June 2008. Sonomatra provides on-site maintenance and repair of power transformers and on-load tap changers, oil analysis, oil treatment and retro filling.

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Product & Services Offered By CromptonThe company is organized into three business groups viz. Power Systems, Industrial Systems, Consumer Products. Nearly, two-thirds of it's turnover accrues from products lines in which it enjoys a leadership position. Presently, the company is offering wide range of products such as power & industrial transformers, HT circuit breakers, LT & HT motors, DC motors, traction motors, alternators/ generators ,railway signaling equipments, lighting products, fans, pumps and public switching, transmission and access products. In addition to offering broad range of products, the company undertakes turnkeyprojects from concept to commissioning. Apart from this, CG exports it's products to more than 60countries worldwide, which includes the emerging South-East Asian and Latin American markets .Thus, the company addresses all the segments of the power industry from complex industrial solutions to basic household requirements. The fans and lighting businesses acquired “Super brand" status in January 2004. It is a unique recognition amongst the country's 134 selected brands by "Super brands" ,UK.

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DIVISIONS OF CGLRegional sales offices located in Distribution Transformer Shunt Reactor Crompton Greaves strength emanates from its business operations consisting of 21 divisions spread across in Gujarat, Maharashtra, Goa, Madhya Pradesh and Karnataka supported by well knitted marketing and service network through 14 branches in state capitals under overall management of four Dry Type Transformer Bulbs, Tubes Ceiling Fans FHP

1) Motors Pumps Street Lighting Chennai.2) Relays Rail Signalling Delhi, Kolkata, Mumbai and3) Stampings HT Motors LT Motors Power Transformer

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BRANCH OFFICES Instrument Transformer

Manufacturing Units

1. Manufacture of Domestic, Agro and Industrial Pumps, Ahmednagar (Maharashtra)2. Manufacturing range of DC M/C and Railway Traction Motors, Mandideep (M.P.)3. Manufacture DC Motors in the range of 1.2 to 450KW, Ahmednagar (Maharashtra)4. Manufacture of Power Transformer and Shunt Reactor, Mumbai (Maharashtra)5. Manufacture of Distribution Transformer, Malanpur (M.P.)6. Manufacture of Power Transformers, Mandideep (M.P.)7. Manufacture of Transformer-AMT Plant, Mandideep (M.P.)8. Manufacture of Stampings for Motors, Mumbai (Maharashtra)9. Manufactures High Voltage Induction Motors, Mandideep (M.P.)10. Signalling Relay Unit, Pithampur (M.P.)11. Luminaire Division, Mumbai (Maharashtra)12. Fans & Appliances Division I, Goa13. Table Fans(Kundaim) Division, Goa 14. FHP Motors Division, Goa15. LT Motors Division, Goa16. Switchgear Division EHV, Nashik (Maharashtra)17. Digital-PSTA Manufacturing, Bangalore (Karnataka)

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CROMPTON GREAVES T2 MALANPUR

Manufacture of  Distribution Transformer ,Malanpur (M.P.)

The new integrated Distribution Transformer division (T2) at Malanpur is spread over 20,000 sq meters .The Malanpur plant manufactures Distribution Transformers up to 20MVA, 66 KV .The consumer products of the plant are customized and are assembled according to the needs of the customers, Job type of production is carried out. Based on function the transformers can broadly be divided into Power transformers, Distribution transformers and other types of special transformers for welding, traction, furnace etc.

1) Low Power Transformers: The power transformers are used to transform power voltage from the generation point to the transmission point and are installed at the generation site right up to the last substation just before distribution activities commence. This transformer is used to either step up or step down power to match the voltage requirements. They are oil filled transformers with its range spanning from 11kV 765kV. Power transformers would account for about 65-68 % of the total value of the transformer industry.

2) Distribution Transformers: A distribution transformer is used to transform power voltage from a substation to final end of consumption. The basic purpose of a distribution transformer is to provide end user with low voltage power. A distribution transformer could either be oil filled or dry type by nature, with range spanning from 1.1 kV to 11kV. Distribution transformer would account for the remaining 32 -35 %of the total value of the transformer industry

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.3) CR Transformers: A dry type transformer is used where there is space constraint and higher chances of occurrence of fire. Special fire resistant insulation is used in this type of transformers .These are mostly used by industrial and corporate clients at software parks, hotels, hospitals ,high rise buildings etc. These transformers are categorized as distribution transformers due to their nature of operation, i.e. at the end users locations

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Production –Design ,Manufacturing and Testing Equipment 

They use state-of-the-art technologies in their in-house design department, and strive to upgrade the products based on customer feedbacks and engineering expertise of their technical teams. Apart from continuous improvement, every effort are being carried out to reduce the input cost by increasing efficiency in manufacturing cycle, reduction of cycle time, reduction of raw material cost and procuring improved products/machines from third-party vendors and so on. Few accomplishments achieved are:

Introduction of CTC conductors have decreased cycle time for windings .Installation of the new oven in 2007 utilizing the "autoclave with Vapor Phase Drying process" which has helped to reduce cycle time of the process of drying active parts from approximately nine days to three days.

 Acceptance NO Specification Technical Design GTP (Guarantee Technical Particular) YES Customer Details Letter of Intend Letter of Acceptance Order Technical Specification of Customer Planning Design Department Bill of Material Purchase CGL uses state-of-the-art technologies in their in-house design department, and they strive to upgrade their products based on customer feedbacks and engineering expertise of their technical teams. The electrical designs are made using Excel software

mechanical drawings are made using the softwares AutoCAD, Inventor and ProE. Apart from continuous improvement, every effort are being carried out to reduce the input cost by increasing efficiency in

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manufacturing cycle, reduction of cycle time, reduction of raw material cost and procuring improved products/machines from third-party vendors and so on. Production Department Production Process Diagram

.Product Design and Planning

Since all transformers are tailor made, on receipt of the customer order, the manufacturer commence designing the transformer as per customer needs. The drawing is then submitted to the customer for approval. The drawing and bill of material are then issued to various departments to carry out further work as per design.

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 TRANSFORMER

Principle:-

A Transformer based on the Principle of mutual induction according to this principle, the amount of magnetic flux linked with a coil changing, an e.m.f is induced in the neighbouring coil.

Construction:-

A transformer consists of a rectangular shaft iron core made of laminated sheets, well insulated from one another. Two coils p1 & p2 and s1 & s2 are wound on the same core, but are well insulated with each other. Note that the both the coils are insulated from the core, the source of alternating e.m.f is connected to p1p2, the primary coil and a load resistance R is connected to s1 s2, the secondary coil through an open switch S. thus there can be no current through the  sec. coil so long as the switch is open.

For an ideal transformer, we assume that the resistance of the primary & secondary winding is negligible. Further, the energy loses due to magnetic the iron core is also negligible.

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INTRODUCTION OF TRANSFORMER

                   A transformer is an electrical device which is used for changing the A.C. voltages. A transformer is most widely used device in both low and high current circuit. As such transformers are built in an amazing strength of sizes. In electronic, measurement and control circuits, transformer size may be so small that it weight only a few tens of grams where as in high voltage power circuits, it may weight hundred of tones.

                  In a transformer, the electrical energy transfer from one circuit to another circuit takes place without the use of moving parts.

                  A transformer which increases the voltages is called a step-up transformer. A transformer which decreases the A.C. voltages is called a step-down transformer.

                  Transformer is, therefore, an essential piece of apparatus both for high and low current circuits.

THEORY AND WORKING OF TRANSFORMER

        When an altering e.m.f. is supplied to the primary coil p1p2, an alternating current starts falling in it. The altering current in the primary produces a changing magnetic flux, which induces altering voltage in the primary as well as in the secondary. In a good-transformer, whole of the magnetic flux linked with primary is also linked with the secondary, then the induced

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e.m.f. induced in each turn of the secondary is equal to that induced in each turn of the primary. Thus if Ep and Es be the instantaneous values of the e.m.f.’s induced in the primary and the secondary and Np and Ns are the no. of turns of the primary secondary coils of the transformer and

         Dфь / dt = rate of change of flux in each turnoff the coil at this instant, we have

         Ep = -Np dфь/dt                             -----------------(1)    And

        Es = -Ns dфь/dt                              ----------------- (2)

Since the above relations are true at every instant, so by dividing 2 by 1, we get

           Es / Ep = - Ns / Np                         ----------------(3)

As Ep is the instantaneous value of back e.m.f induced in the primary coil p1, so the instantaneous current in primary coil is due to the difference (E – Ep ) in the instantaneous values of the applied and back e.m.f. further if Rp is the resistance o, p1p2 coil, then the  instantaneous current Ip in the primary coil is given by

                                     Ip      =   E – Ep / Rp  

                                 E – Ep   =   Ip Rp

When the resistance of the primary is small, Rp Ip can be neglected so therefore

                                 E – Ep   = 0 or Ep = E[16]

Thus back e.m.f  = input e.m.f

Hence equation 3 can be written as

            Es / Ep = Es / E = output e.m.f / input e.m.f = Ns / Np = K

Where K is constant, called turn or transformation ratio.

In a step up transformer

                              Es > E  so K > 1, hence Ns > Np

In a step down transformer

            Es < E  so K < 1, hence Ns < Np

If          Ip   =     value of primary current at the same instant t

And      Is    =      value of sec. current at this instant, then

       Input power at the instant t              =       Ep Ip and

       Output power at the same instant    =      Es Is

If there are no losses of power in the transformer, then

              Input power = output power        Or 

               Ep Ip   =     Es Is               Or  

               Es / Ep    =     Ip / Is    =    K

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In a step up transformer

                              As  k > 1, so Ip > Is or Is < Ip

i.e. current in sec. is weaker when secondary voltage is higher.

Hence, whatever we gain in voltage, we lose in current in the same ratio.

Similarly it can be shown, that in a step down transformer, whatever we lose in voltage, we gain in current in the same ratio.

Thus a step up transformer in reality steps down the current & a step down transformer steps up the current.

Efficiency:-

Efficiency of a transformer is defined as the ratio of output power to the input power. i.e.

                η   =    output power / input power   =    Es Is / Ep Ip

Thus in an ideal transformer, where there is no power losses, η  =  1. But in actual practice, there are many power losses, therefore the efficiency of transformer is less than one.

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ENERGY LOSSES:-

Following are the major sources of energy loss in a transformer:

1. Copper loss is the energy loss in the form of heat in the copper coils of a transformer. This is due to joule heating of conducting wires.

2. Iron loss is the energy loss in the form of heat in the iron core of the transformer. This is due to formation of eddy currents in iron core. It is minimized by taking laminated cores.

3. Leakage of magnetic flux occurs inspite of best insulations. Therefore, rate of change of magnetic flux linked with each turn of S1S2 is less than the rate of change of magnetic flux linked with each turn of P1P2. 

4. Hysteretic loss is the loss of energy due to repeated magnetization and demagnetization of the iron core when A.C. is fed to it.

5. Magneto striation i.e. humming noise of a transformer.

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USES OF TRANSFORMER

            A transformer is used in almost all a.c. operations

        In voltage regulator for T.V., refrigerator, computer, air conditioner etc.

            In the induction furnaces.

        A step down transformer is used for welding purposes.

        A step down transformer is used for obtaining large current.

        A step up transformer is used for the production of X-Rays and NEON advertisement.

        Transformers are used in voltage regulators and stabilized power supplies.

        Transformers are used in the transmissions of a.c. over long distances.

        Small transformers are used in Radio sets, telephones, loud speakers and electric bells etc.

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Manufacturing process

a)Core Building CRGO (Cold Rolled Grain Oriented) steel sheets are used for manufacturing core laminations by the subcontractors. They cut required size of laminations by high accuracy shears. Laminations are stacked instep lap -interleaved fashion to minimize core losses, exciting current and noise level. The yokes and limbs are firmly clamped between steel channels in manner, which reduces vibration, and inherent noise

CRGO laminated silicon steel

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CORE assembly

.

b)Winding Annealed/half-hard copper conductors either in the form of a strip or round wires are used in winding operations and dimensions for the winding such as inside diameter and outside diameter are maintained by selecting proper Mandrel. Insulation is provided as mentioned in the design output. The coil tapping leads and phase leads are taken out according to the design output. Coils are kept under clamping pressure and sent for ovening

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FORMER

Winding conductor

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Coils

c) Preparation of insulating material Pre compressed boards, perma wood (un-impregnated identified laminated wood which can with stand temperatures of upto 1100c); craft paper, crepe paper, etc. are used as insulating material. Components such as cylinders, wedges, spacers, rings etc. are made from these materials by different operations like cutting, edge rounding, chamfering, drilling, machining etc.

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Insulation paper

d) Core Coil Assembly The coils are concentrically assembled on the core limbs as per the design details. The core and coil assembly is rigidly supported and clamped. The main leads and tapping leads of coils are then connected to bushings and the tap changers respectively. All these leads are properly clamped and insulated to ensure required electrical clearance and creepage .A tap changer is a selector switch that allows the voltage ratio of the transformer to be changed by increasing or decreasing the turns of the winding. The tapping leads of the coils are connected to the tap changer to allow the additional turns to be brought into or taken out of circuit. In some distribution transformers , the tap changer switch is an off load manual switch , while in others , the tap changer is an on-load automatic switch.

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e)Tank finish and paintings

After welding , tanks are preheated by slot blasting. They are thoroughly cleaned before applying a coat of zinc chromate primer paint on external surface . one coat of weather resisting enamel finish paints is applied . the final coat of external paint is applied , priorto dispatchof ready transformer fitted with accessories and fittings.

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f) Ovening

Hot air drying is carried out to remove moisture from the active parts of the transformers . For transformers up to 33kv class drying is carried out in well ventilated ovens for a period till insulation resistance builds up to specific value. For large transformers , above 33kv class, drying takes place in vaccum drying oven . the core - coil assemblyis initially heated for a predetermined period by admitting heated kerosene vapour . And then they are placed under vaccum , this cycle is repeated till all theMoisture is extracted .

g)Tanking

Active part(Core coil assembly) after drying are placed in tank. Bushings of specified rating are mounted on top o side as per design are connected to end terminals . tap changing switch is provided and connected to various tapping leads as per design. The top plate is tightened at specific torque and the filtered oil is filled under vacuum . the tank is tested for leackage by subjecting it to the required pressure after all other accessories are fitted on the tank. The oil is used for further insulating purposes plus the removal of heat from the windings. The assembly of the windings on the core allows gaps to enhance the oil circulation around the windings . the tank is constructed with fins or tubes to allow better circulation of oil and to provide a greater surface area for contact with the cooling air.

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h)Testing

We have state of the art testing facilities including a fully equipped testing room for carrying out of all routine tests such as temperature rise test , zero phase sequence test etc. every transformer is tested for routine tests specified in standard specification on the completion which a tst certificate to this effect is issued All transformers are tested in our sophisticated laboratory for the following routine tests conforming to National and International Specifications on the completion of which a test certificate to this effect is issued. Voltage Ratio, Winding resistance. Impedance Voltage, No load and Load Losses, No load Current ,Dielectric tests. Factory Pass Collection of Payment After the acceptance of the order from the customer, the company starts the assembling of the transformer according to the technical specification of the customers; after the assembling and testing is completed the finance department issues an invoice and performs3major functions:39CG -Transformer designs are proven for dead short circuits by tests conducted at the independent ,accredited short circuit laboratory of the Government of

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India.

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FinanceInvoice Commercial Invoice Central Excise Duty CustomerPayment of Central Excise Duty: The finance department makes sure that the central excise duty on the products is paid tothe competent authorities, only when the duty fees is paid the product is allowed to pass from the factory gate. Commercial Invoice: The finance department also issues a Commercial Invoice a copy of it sent to the branch office and the other copy is sent to the customer. The payment from the customer is received on the basis of the terms of payment and other details mentioned in the invoice.

SixSigmaThe company focuses upon improving the quality of its products hence it appointed an external consultancy company SIX SIGMA Consultant Inc. to eliminate the defects in its projects. The Six Sigma started in 2002 in CGL and was instated in Malanpur Divison in 2002. The employees in this department are designated as Black Belts (for people who are higher in hierarchy) and Green Belts for the people who are lower in hierarchy at the divisional level. The department is the company is supervised by the MD himself. The problems in the production process are handled in the forms of projects and the department has to think out-of-the-box to find solution to the problems. The following methodology is used to remove defects :

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DMAIC Methodology

 Define the problems The department forms cross-functional teams to identify the problems. These teams use the Process Map to identify the key problematic areas. The problems are defined as :Y=f(x)Where X are the various factors which are responsible for the problem Y and these Xs may  bein thousands .A tool knows as CED (Cause-Effect Diagram) or Fishbone Diagram is used to define Xs. Fishbone Diagram Environment Measurement Method Material Man Machine DEFECT The various Xs are defined from the fields listed above in the diagram.

 Measure and Analysis To measure the impact of the various Xs FMEA tool (Failure Mode & Effect Analysis) is used. This tool uses 3parameters to determine the ratings:

Severity of Y Frequency or Occurrence of X Detection of X (As the detection of X increases its rating decreases)On the basis of these parameters the RPN ( Risk Priority Number) of various problems is determined. The various Xs listed are categorically divided with the help of benchmark line according to the reducing affect of the X on the problem Y. The scrutinized Xs are subjected to various statistical tools to obtain the major Xs in order to find the real-life solutions to the problems.

 Improve & Control The factors obtained are the major areas which can be improved and controlled to achieve the better quality products. The

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company implements six sigma in every aspect of its functioning to offer best services and quality to its customers. For eg: The Green Belt supervises the IPQ (In-house Process Quality) in its divisions. Other than this the Suppliers are rated according to SQP (Supplier Quality Process) in which various Clauses are defined which need to be satisfied by the supplier only then it can be a supplier to thedivison.41The CTQ (critical to quality) raw materials are supplied only by the suppliers who are able to clear the75% cut-off in the listed clauses while this is 65%for the non-CTQ raw material suppliers. On an average a project takes about 3months for completion and the half the time i.e. 1.5 months is spent in identifying the problems

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