Value Stream Mapping at Siemens Ltd

1

TRAINING & PROJECT REPORT

Presented by

Nakul Modani

Based on the training undertaken in

Siemens Ltd.

Project

Value Stream Mapping

Period

From January 27, 2009 to April 27, 2009

Industry Guide

Mr. Mangesh Patil

Faculty Supervisor

Prof. S. Naik

SVKM’s NMIMS University

Mukesh Patel School of Technology Management & Engineering

Vile Parle (W), Mumbai 400 056

9th

Trimester – MBA(Tech)

2

TRAINING/ PROJECT APPROVAL SHEET

This is certify that

Shri/Smt./Kum: Nakul Modani

Roll No. / Exam Seat No.: 310

has completed the training & project in our company as mentioned below:

Siemens Ltd.

and the training report is also submitted in partial fulfillment of

9th

Trimester Industrial Training for MBA (Tech) in Manufacturing sector

and the same is approved (name/signature of Industry Mentor/HR Department)

Mangesh Patil Abhijeet Deherkar

Date:-

Place:

Company Seal:

For SVKM‟s NMIMS University:

I have supervised and guided the student and reviewed the report and approve the same:

(Faculty Supervisor) (HOD)

---------------------------- -------------------------------

Date:

Place

Seal of NMIMS University:

9th

Trimester – MBA (Tech)




3

TRAINING/PROJECT REPORT

Submitted in Partial – Fulfillment of the Requirements for

9th Trimester Industrial Training for MBA (Tech) - Manufacturing

Name of the Student: - Nakul Modani

Roll No: - 310

Exam Seat No :-

Academic Year : - 2008-09

Name of the Department: - Manufacturing

Name and Address of the Company: - Siemens Ltd.,

P.O. Box No. 85

Thane-400 601

India.

Training Period From : - 27th January 2009 To 27th

April 2009

THIS IS TO CERTIFY THAT

Shri/Smt./Kum: _________Nakul Modani

Exam Seat No _____________ has satisfactorily Completed his/her Training/Project Work

submitted the training report and appeared for the Presentation & VIVA as required.

External Examiner Internal Examiner Head of Dept. Chairperson/Dean

Date

Place:

Seal of University:

9th

Trimester – MBA(Tech)




4

ACKOWLEDGEMENT

I take great pleasure in submitting the report of IXTH

trimester technical training in SIEMENS

Ltd. My training is giving me an exposure to the actual prevailing conditions in the industry

and helping me to check the feasibility of the theories learnt during my engineering studies.

A lot of people helped me in this training and I would like to thank them all. I am grateful to

Mr. Abhijeet Deherkar (Personnel Dept), SIEMENS LTD. - KALWA WORKS for giving

me the opportunity to undergo training in this esteemed organization.

I would like to thank Mr. Mangesh Patil, Mr. S. Tellis, Mr. G.K. Srinivasan and all

workmen for their co-operation and guidelines, which made my training process continual

and exciting. I would like to thank them for believing in me, giving me the support,

encouragement and guidance, which helped me in carrying out my training successfully. It is

indeed a moment of great pleasure and immense satisfaction for me to express a sense of

profound gratitude and indebtedness to all the people on the shop floor, who contributed in

making my Training a rich experience.

I sincerely thank Mrs. Shobna Poddar, Training & Placement officer for giving me an

opportunity of training at SIEMENS LTD., Kalwa.

I am very thankful to my TRANING GUIDE, Prof. S. Naik Sir, who gave us RIGHT

DIRECTION & STRONG SUPPORT during this training period.

(Nakul Modani)

Date:

Place:

5

Siemens Ltd.

KALWA, THANE

There Is More to a SIEMENS

Motor Than Just Horsepower!

NAKUL MODANI

INPLANT TRAINING REPORT

(27/01/2009-27/04/2009)

WMOT DIVISION

6

Contents

Sr. No. Topic Page No.

1 Introduction to Siemens 8

2 Introduction to Value Stream Mapping 23

3 Press Shop 34

4 Winding Shop 44

5 Machine Shop 54

6 Assembly Shop 63

7 Results 73

8 Bibliography 74

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Synopsis

During my training of three months at Siemens Ltd, Kalwa Works, I was posted in the

Manufacturing department under the guidance of Mr. Mangesh Patil. I was entrusted with the

project of Value Stream Mapping.

For performing the Value Stream Mapping at the shop floor I had to understand the

manufacturing procedures on the shop floor thoroughly. Also I had to understand the flow of

material as well as the information on the shop floor. Based on my understanding of the

manufacturing processes I had to map the processes on the shop floor and create a current

state map of the processes in each shop.

Based on the current state maps I was supposed to find the defects in the present

system and also find a solution to correct them. After correction I also had to take the

feedback from the production planning department and the process planning department.

Based on their feedback I had to develop the future state map and also had to check the

feasibility of the same by discussing it with the shop incharges and the workers.

Post the feedback from the workers I had to make the necessary changes the future

state map. Also the recommendations were to be implemented in the shop in a decided order.

My main target during the training was to ensure that the waste in the manufacturing

processes of the motor were reduced to the minimum possible level without disturbing the

flow of the material and information on the shop floor.

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Chapter 1

Introduction to SIEMENS

Formed in 1847, the company Telegraphenbauanstalt von Siemens & Halske grew

within the space of a few decades from a small precision-engineering workshop, producing

mechanical warning bells for railways, wire insulation made of gutta-percha, and electrical

telegraph systems, into one of the world‟s largest companies in electrical engineering and

electronics. Landmark inventions, an immense readiness to innovate, and a strong

international commitment have driven the company‟s success since its very beginnings.

When in 1866 Werner Siemens (known as Werner von Siemens after 1888) discovered

the dynamoelectric principle, the potential applications for electricity were limitless. Heavy-

current engineering began to develop at a breathtaking pace, producing one triumphant

innovation after another. In 1879, Siemens & Halske presented the first electric railway and

installed the first electric streetlights in Berlin; in

1880 came the first electric elevator; and in 1881 the

electric streetcar. Following the death of the

company‟s founding father, Werner von Siemens, in

1892, his successors followed the course he had set,

constantly advancing the company with trailblazing

innovations.

Lighting, medical engineering, wireless

communication, in the 1920s and , household

appliances, were followed after World War II by

components, data processing systems, automotive

systems and semiconductors. The guiding principle

that had applied since the company‟s beginnings - of

concentrating solely on electrical engineering, "but

on the whole of electrical engineering" - helped

make Siemens the only company in its industry to

operate in both light- and heavy-current electrical

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engineering, and by the mid-1920s it was again one of the world‟s five leading companies in

its field.

When the National Socialists seized power, Siemens, like the rest of German industry,

was drawn into the system of the war economy. Post World War II, Siemens began

rebuilding in Germany first, but gradually moved into foreign countries from the 1950s on.

Technological advances, expansion into new business segments, and the reestablishment of a

presence in traditional export markets laid the foundations for the company's return to its old

strength in the world marketplace in the 1960s. To give the company a stronger identity and

consistent market presence, Siemens & Halske, Siemens-Schuckertwerke AG, and Siemens-

Reiniger-Werke AG, the three main companies in the group, merged in1966 to form Siemens

AG. Today, Siemens is a transparent organization comprising fast-acting business units that

is making important and significant contributions to the future of electrical engineering and

electronics.

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HISTORICAL PERSPECTIVE

1857 - SIEMENS found in GERMANY.

1867 - SIEMENS first linkage in INDIA.

1954 -Assembly and repair undertaken in small workshop under Mahalakshmi Bridge

Bombay.

1957 - Switchboards manufacturing began at Worli, Bombay.

1959 - Medical equipments added to the range at Worli.

1960 - Manufacturing of Switchgear began at Worli, Bombay.

1963 - Switch board manufacture transferred to Chakala, Andheri.

1966 - First batch of Electric Motors produced at Kalwa.

1973 - Transfer and expansion of Switchgear production at Kalwa.

1975 - Transfer and expansion of Switchboard production at Kalwa.

1977 - Manufacturing of electronic equipments at Worli, Bombay.

1984 - Manufacturing of Switchboard started at Nasik.

1986 - Manufacturing of Railway Signaling Products.

1986 - Heavy investment in Tool room and production shop with the inception of NC and

CNC machine.

1991 - New Switchgear factory in Aurangabad.

1993 - Assembly workshop, Medical products - Goa.

1995 - Launching of Mobile phones.

2005 – Traction motors unit started.

2006 - Transformer factory shaping up to meet industrial needs.

2009 – 1.875MW prototype successfully tested.

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SIEMENS IN KALWA

SIEMENS, Kalwa Works comprises of three manufacturing units viz.

Switchgear Plant (WSGR).

Switchboard Plant (WSWB).

Motors Plant (WMOT).

SWITCHGEAR PLANT:

At the Switchgear factory a wide range of low and high tension equipments are

produced. The low tension Switchgear range consists of contactors, bimetal relays, starters,

circuit breakers, fuse switches, motor control gears like push buttons, pilot lamps limit

switches, HRC fuses, fuse bases, etc.

SWITCHBOARD PLANT:

SIEMENS switchboards have established remarkable leadership in the market. This

happens through a deep understanding of the customer‟s requirement, resulting in customer-

oriented products design manufactured with latest technology at par with international

standard. This unit manufactures switchboards and circuit breakers with different ranges. The

switchboard is an electrical panel consisting of elements like potential transformers, current

transformers, circuit breakers, timers etc.

MOTOR PLANT:

The motor factory produces high quality motors with economical energy

consumption, resilient enough to withstand wide voltage and frequency fluctuations. The

factory is equipped with dedicated and general-purpose CNC machines that ensure accuracy

at the micron level. Computerized on the line production planning and control system ensures

a built in quality from the very beginning. The factory has been awarded the ISO-9001

certification.

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ROLE OF VARIOUS DEPARTMENTS IN MOTORS:

These are the various departments which contribute towards achieving a complete

finished product besides the ones on the shop floor viz.

1) Product development:-

Introduction and development of new products.

Specifications / Statutory requirements check.

Electrical design & electrical group drawings.

Special test co-ordination.

Consult customers for product specification.

2) Process planning:-

Induction of new technology or equipment.

Development of tooling.

Upgrading of equipments.

Disposal of obsolete equipments.

Tool, Jigs, Fixtures design.

Time standards (MOST).

Create, change routing in ERP system.

Shop performance analysis.

Design and modify workplace layout.

3) Commercial:-

Contract management.

Sourcing strategies.

Cost control and cost reduction.

Procurement of capital goods and indirect material.

Vendor management.

Manage MIS and reports.

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4) Vendor development:-

New vendor evaluation and selection.

Component development.

Vendor audits.

Vendor self certification.

Upgrading of vendors on basis of infrastructure and process.

5) Manufacturing:-

Manufacturing of components.

Assembly of manufactured and brought out items.

Co-ordination with process planning department for manufacturing processes.

6) Quality Management:-

Release and upgradation of FA charts.

Manage internal and external audits.

Testing of materials.

Lab facilities management.

Implementation of EMS.

7) Outsourced Products:-

Identify training need and provide training.

Communicate all plans and changes.

Identify and appreciate achievers.

Resolve internal problems and maintain harmonious industrial relations.

8) Plant Engineering:-

Preventive and breakdown maintenance of equipments.

Spares management.

Annual maintenance contracts.

Provide service for internal movement of material.

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DESCRIPTION OF SIEMENS MOTOR:

Siemens motors are high quality machines with economic power consumption and are

resilient enough to withstand wide voltage and frequency fluctuation, a condition widely

prevalent in India. The user-friendly designs are proof of the fact that Siemens has a

considerable knowledge of the industries, which use their motors.

Induction motors manufactured by Siemens Ltd. are robust in construction and

streamlined in appearance. They are designed, manufactured and tested to high technical

standards and are suitable for all general, industrial and agricultural application.

The three phase induction motors are available from 5.5 kW to 1.875 MW in the

synchronous speed of 750, 1000, 1500, and 3000 R.P.M. These motors have been approved

by ISI and conform to IS: 325 / 1978 for electrical performance and to IS: 1231 / 1967 for

dimensions and are provided with standard class F insulation.

Motors are provided with PTC (Positive Temperature Co-efficient), BTD (Bearing

Temperature Detector) and ACH (Anti Condensation Heater) in the stator winding as a

protection circuit wherever specified. These motors are of TEFC, TENC, DP, and TEAOM

type. The housing is provided with ample cooling fins evenly distributed over the complete

surface for better heat dissipation. For easy handling a lifting hook is provided on the top of

the casting.

The motors have an Aluminum pressure die-cast or copper bar rotor and are

dynamically balanced. A uniform rotor - stator air gap and vibration free operation is

maintained generally conforming to IS: 4769 / 1968. The rotor is specially treated for rust

prevention, i.e. a coat of red oxide is applied over the balanced rotor.

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The stator core is of wound fine enameled copper wire with slot insulation of superior

grade insulating material such as Polyester film, Nomex-Polyester-Nomex. Bearings of

reputed make and ample loading capacity are fitted after selective inspection. The terminal

box provided facilitates easy wiring.

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SALIENT FEATURES OF SIEMENS MOTOR:

1. Recipient of ISI mark (IS: 325 / 1978) for standard motors up to 425 kW in F class insulation.

2. Siemens use only pressure die-cast and copper bar rotors which are dynamically balanced.

3. Cleaned stator stacks, pre - wound and hydraulically pressed in cast iron frame ensure better

stacking factor, even and uniform air-gap, closer tolerance and correct fits.

4. Connection by electric brazing eliminates loose connections and ensures firm contacts unlike

problems

5. Bearings are shrunk fit (by preheating with the help of induction heating equipment) on

bearing seat ground to close tolerance and correct fits. Normally prevalent in soldering.

6. Slot insulation by polyester films only, all sleeves are of varnished fiberglass.

7. All major raw materials like ball bearings, copper wire, insulating materials, are purchased

directly from reputed manufacturers only.

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Nomenclature of SIEMENS Motor:

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TYPES OF CONSTRUCTION OF MOTORS

IMB3 CONSTRUCTION

In this type of construction, the motor rests on the foot. The

motors with such type of construction are also known as foot

mounted motors.

IMB5 CONSTRUCTION

In this type of construction, the motor rests with the help of the

flange. The flange is clamped to any vertical surface with the help

of bolts.

IMB35 CONSTRUCTION

In this type of construction, the motor is equipped with the foot as

well as flange. The flange is coupled to a coupling. The position of

the shaft in this type of construction is horizontal.

IMV5 CONSTRUCTION

In this type of construction, the foot of the motor is clamped to a vertical

surface. The position of the shaft is vertically downwards. This is also a

foot-mounted motor.

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IMV6 CONSTRUCTION

In this type of construction, the foot of the motor is clamped to vertical

surface. In this type, the position of the shaft is vertically upwards. This is a

foot-mounted motor.

IMB6 CONSTRUCTION

In this type of construction, the position of the shaft is towards the right of the

foot, which is mounted on the wall. This is also a foot-mounted motor.

IMB7 CONSTRUCTION

In this type of construction, the position of the shaft is towards the left of the

foot, which is mounted, on the wall. This is also a foot-mounted motor.

IMV1 CONSTRUCTION

In this type of construction, there is a flange being mounted. The direction of

the shaft of the motor is vertically downwards. In this type there is no

mounting foot provided.

IMVI

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BASIC PRINCIPLE: -

When the three phase stator windings are fed by a three-phase supply, a magnetic flux of

constant magnitude but rotating at synchronous speed is set up. The flux passes through the

air gap, sweeps past the rotor surface and cuts the rotor conductors. Due to the relative speed

between the rotating flux and the stationary conductors, an electromotive force is induced in

the conductors, according to the Faradays law, because of the closed circuit rotor, a rotor

current is produced whose direction as given by the Lenz‟s law (“it opposes the very cause

producing it”). The cause here is the relative speed between the rotating flux of the stator

and the stationary conductor of the rotor. Hence to reduce the relative speed, the rotor starts

rotating in the same direction as that of the flux and tries to catch up with rotating flux. The

shaft through the rotor is used to transmit the rotary mechanical power to drive machines.

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Induction AC Motors

AC motors typically feature rotors, which consist of a laminated, cylindrical iron core with

slots for receiving the conductors. The most common type of rotor has cast-aluminum

conductors and short-circuiting end rings. This AC motor "squirrel cage" rotates when the

moving magnetic field induces a current in the shorted conductors. The speed at which the

magnetic field rotates is the synchronous speed of the AC motor and is determined by:

Ns = 120*(f/p)

Where,

Ns = Synchronous speed

f = Frequency, and

p = Number of Poles.

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CHAPTER 2

Introduction to Value Stream Mapping

A Value Stream is the set of all actions (both value added and non value added)

required in bringing a specific product or service from raw material through to the customer.

Value Stream perspective means working on the big picture, not just individual processes,

and improving the whole, not just optimizing the parts. Value Stream is a pencil paper tool

that helps one to see and understand the flow of material and information as a product makes

its way through the value stream.

The value stream mapping (VSM) method is a visualization tool oriented in Toyota

Production System (TPS). It helps to understand and streamline work processes by using the

tools and techniques of lean manufacturing. The goal of VSM is to identify, to demonstrate

and to decrease waste in the process. Waste is defined as any activity that does not add value

to the final product. VSM can thus serve as a starting point to help Managers, Engineers,

Production Associates and Schedulers to recognize waste and identify its causes. As a result,

VSM is primarily a communication tool, but it can also be used as a strategic tool

In order to do this, the VSM method visually maps the flow of material and information.

From the moment products are entering the back door as raw materials, via all manufacturing

process with cycle time until the product leaves as a finished product.

Mapping the processes with cycle time, down time, in-process material movement,

information flows, helps visualize current state of process activities and guides toward the

future desired state. The process usually includes mapping the “current state” and the “future

state”. These then serve as a foundation for other lean manufacturing strategies.

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History of Value Stream Mapping

The use of waste removal to achieve competitive advantage inside organizations was

pioneered in the 1980s by Toyota's chief engineer, Taiichi Ohno, and sensei Shigeo Shingo

and is oriented fundamentally towards productivity rather than towards quality. The reason

for this is thought to be that improved productivity leads to leaner operations which help to

expose further waste and quality problems in the system. Thus the systematic attack on waste

is also a systematic assault on the factors that are underlying poor quality and on fundamental

management problems.

The seven commonly accepted wastes in the Toyota production system were originally:

Overproduction (faster than necessary pace).

Waiting.

Transport (conveyance).

Inappropriate processing.

Unnecessary inventory (excess inventory).

Unnecessary motion.

Defects (correction of mistakes).

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Seven Value Stream Mapping Tools

Process activity mapping.

Analyze the process and record all the details like distance, time and people.

Classify processes as operation, transportation, inspection, delays, storage and

identifies cycle time, set-up time and manpower.

Trace production flow and/or information flow

Simplify the flow by eliminating and/or combining the activities.

Supply chain response matrix.

Determine lead time for a product internally and externally

Determine the average amount of standing inventory at specific points in the supply

chain.

Reduce both the lead-time and standing inventory.

Production variety funnel.

Plot number of variants at each tier of suppliers

Help in understanding of how the supply chain operates for the given product

Identify buffer stock of various components and subassemblies.

Decide where we can reduce inventory and make change in processing of products.

Quality filter mapping.

Identify where quality problems exist in value stream.

Classifies defects as product, service or internal scrap.

Analyzes where in the supply chain defects occur.

Establishes both internal and external quality levels.

Demand amplification mapping.

Find delays and poor decision making concerning information and material flow.

Analyze the extent of amplification as orders move upstream.

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Decision point analysis.

Determine where in the value stream, the flow goes from push system to pull system.

Help in analyzing the „what if‟ scenarios to view the operation of value stream when

the decision point is moved along the value stream for better design.

Analyze where in value stream excess inventory exist.

Physical structure mapping.

Provide an overview of the value stream.

Determine how the cost structure and volume structure look like along the value

stream. In both the structures assembler is located in middle of supplier tiers and

distribution tiers.

Help in finding waste due to the overall structure of industry and eliminate the waste.

Requirements

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Symbols used in value stream mapping

VSM Process Symbols

Customer/Supplier

This icon represents the Supplier when in the upper left, the

usual starting point for material flow. The customer is

represented when placed in the upper right, the usual end point

for material flow.

Dedicated Process

This icon is a process, operation, machine or department,

through which material flows. Typically, to avoid unwieldy

mapping of every single processing step, it represents one

department with a continuous, internal fixed flow path.

Workcell

This symbol indicates that multiple processes are integrated in a

manufacturing workcell. Such cells usually process a limited

family of similar products or a single product. Product moves

from process step to process step in small batches or single

pieces.

VSM Material Symbols

Inventory

These icons show inventory between two processes. This icon also

represents storage for raw materials and finished goods.

Shipments

This icon represents movement of raw materials from suppliers to the

Receiving dock(s) of the factory. Or, the movement of finished goods

from the Shipping dock(s) of the factory to the customers

Push Arrow

This icon represents the "pushing" of material from one process to the

next process. Push means that a process produces something regardless

of the immediate needs of the downstream process.

Supermarket

This is an inventory 'supermarket" (kanban stockpoint). Like a

supermarket, a small inventory is available and one or more downstream

customers come to the supermarket to pick out what they need. The

upstream workcenter then replenishes stocks as required. When

continuous flow is impractical, and the upstream process must operate in

batch mode, a supermarket reduces overproduction and limits total

inventory.

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Material Pull

Supermarkets connect to downstream processes with this "Pull" icon

that indicates physical removal.

FIFO Lane

First-In-First-Out inventory. Use this icon when processes are connected

with a FIFO system that limits input. An accumulating roller conveyor

is an example. Record the maximum possible inventory.

Safety Stock

This icon represents an inventory "hedge" (or safety stock) against

problems such as downtime, to protect the system against sudden

fluctuations in customer orders or system failures. Notice that the icon is

closed on all sides. It is intended as a temporary, not a permanent

storage of stock; thus; there should be a clearly-stated management

policy on when such inventory should be used.

External

Shipment

Shipments from suppliers or to customers using external transport.

VSM Information Symbols

Production

Control

This box represents a central production scheduling or control

department, person or operation.

Signal Kanban

This icon is used whenever the on-hand inventory levels in the

supermarket between two processes drops to a trigger or minimum

point. When a Triangle Kanban arrives at a supplying process, it signals

a changeover and production of a predetermined batch size of the part

noted on the Kanban. It is also referred as "one-per-batch" kanban.

Kanban Post

A location where kanban signals reside for pickup. Often used with

two-card systems to exchange withdrawal and production kanban.

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VSM General Symbols

Operator

This icon represents an operator. It shows the number of operators

required to process the VSM family at a particular workstation.

Other

Other useful or potentially useful information.

Timeline

The timeline shows value added times (Cycle Times) and non-value

added (wait) times. Use this to calculate Lead Time and Total Cycle

Time.

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WHERE CAN VALUE STREAM MAPPING BE USED?

Value Stream Mapping is commonly used in Lean environments to identify opportunities for

improvement in lead time.

Although Value Stream Mapping is often associated with manufacturing, it is also used in

logistics, supply chain, service related industries, healthcare, software development, and

product development.

The value adding steps can be drawn across the centre of the map and the non-value adding

steps be represented in vertical lines at right angles to the value stream. Thus the activities

become easily separated into the value stream, which is the focus of one type of attention and

the „waste‟ steps, another type. Value stream is the process and the non-value streams the

operations. The thinking here is that the non-value adding steps are often preparatory or

tidying up to the value-adding step and are closely associated with the person or

machine/workstation that executes that value adding step. Therefore each vertical line is the

'story' of a person or workstation whilst the horizontal line represents the 'story' of the product

being created.

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WHY TO USE VALUE STREAM MAPPING?

It helps you visualize more than the single process level i.e. the whole process flow.

Mapping helps you not only see waste but also the source of waste in the value stream.

Provides a common language for talking about manufacturing processes.

It ties together lean concepts and techniques.

It shows the linkage between information flow and material flow.

SCOPE OF VALUE STREAM MAPPING

The project is aimed at mapping understanding the current processes of induction

motors and windmill generators manufacturing. Thus VSM will give the current state maps.

Current state maps will enable locating waste in form of inventory, waiting time,

transportation and overproduction at every step of the manufacturing process. From this

mapping we shall derive the future state maps which shall have minimum possible

manufacturing waste.

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STEPS IN VALUE STREAM MAPPING

Value stream mapping consist mainly of four steps, viz.

1. Selecting a product or product family:

Before starting the value stream mapping process one product or product family is to be

selected which will be mapped. Mapping all the products together is not possible because

drawing all the product flows on one map will be complicated, unless one has a small one

product shop floor. Value stream mapping means walking and drawing the processing

steps (material and information) for one product family (group of products that pass

through similar processing steps and over common equipment in downstream processes)

from door to door in the plant.

2. Create a current state map:

Mapping begins at the level of door to door flow in the plant. Current state mapping

includes mapping the process categories instead of recording each processing step.

Symbols or icons shown before are used to represent the process and flows. Some tips to

be used while mapping the current state:

I. Information regarding the current state should always be collected by walking along the

pathway of material and information flow.

II. Begin at the shipping end and work upstream instead of starting at the receiving dock and

walking downstream.

3. Create the future state map:

The purpose of value stream mapping is to highlight sources of waste and eliminate them

by implementing the future state within a short period of time. The purpose is to build a

chain of production where every process is linked to their customer(s) either by continuous

flow or pull and each process gets as close as possible to produce only what its customer

need and only when they need it.

33

To prepare the future state a list of questions is needed like:

Will the workstation produce to a finished goods market where a customer just pulls or

directly to ship to customer?

Where can you use continuous flow processing?

Where will you need a supermarket pull system?

At what point in the production chain will you need production planning?

What process improvements will be necessary?

4. Achieving the future state map:

Value stream mapping is just a tool. Unless one implements the future state that he/she has

drawn, the value stream mapping is useless. In implementing the future state map the map

is broken into steps and the implantation sequence is developed.

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Chapter 3

PRESS SHOP

Press shop is the origin of motor manufacturing. The shop has dynamo steel coils as

inputs which are then converted to blanks and processed further to give stator packets and die

cast or copper bar rotors as output.

The processes in the press shop are as under:

a. Blanking:

Stator blanks are created in this operation from the coiled dynamo steel sheets. One machine

at this workplace satisfies the requirement of the entire plant. The shaft hole is also punched

out from the blank in the operation.

b. Stator Notching:

The Blanks from the previous operation are the input to the process. There are four stator

notching machines in the shop. Some of the laminations of higher sizes are outsourced. The

notched stator lamination is then further sent for stator packetting and the rotor blanks are

sent for rotor notching.

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c. Rotor Notching:

The rotor blanks from the stator notching operations are the inputs to this operation. There are

four rotor notching machines in the shop. Some lamination notching operations are

outsourced. The notched laminations are then sent for either die casting or preheating for

shaft insertion.

d. Stator Packetting:

The notched laminations are converted into packets of desire height. There are three pressing

machines which cater to the needs of the packets. The stator packets after deburring would be

sent to the winding shop for stator winding and impregnation process.

e. Die Casting/Copper bar Insertion:

The Rotor laminations after notching are sent for either aluminum die casting or copper bar

insertion. After this operation they would be sent to the machine shop for turning / shaving

operation.

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OBSERVATIONS

1. After the stator notching operation the laminations are kept without arranging on the table.

2. After the packeting operation the small stator packet go to the deburring section on a

conveyor but the large packets have to be transported on forklift.

3. The inventory at every workstation was enough to last for about 3 to 3.5 shifts.

4. Motor of frame size 25, 28, 31 four pole comprise of 75% to 80% of production. Hence to

control inventory these motors have to be targeted.

5. Whenever a die is set on the blanking machine approximately 100,000 to 150,000 blanks are

created and then the die is send for regrinding. The die set once sent to the tool room for

regrinding takes about 8 days to be operational again.

Based on the observations made in the press shop the current state mapping (1LA0 254-4,

1LA0 284-4 and 1LA0 314-4 motors) of the operations in the press shop is done.

40

RECOMMENDATION

1. After notching the stator laminations, the laminations should be kept in a fixture which can

directly be used for stator packeting. This would save the time in arranging of laminations.

This would result in reduction of stator packeting time by about 15%. This would also result

in rationalizing the SMH by about 600 hours per annum.

2. A passage to be formed between the packeting area and the deburring station so that stator

packets with bigger frame size can be transported with the help of a Jib crane to reduce

material movement.

3. Instead of having 100,000 to 150,000 blanks WIP inventory at a time. We can have 30,000 to

40,000 blanks and then send the die for regrinding. This will prevent heavy grinding cuts and

also would act as a preventive maintenance for the die set.

4. Kanban to be implemented between the stator notching & packetting and Die Casting &

Rotor notching work stations. This will ensure no production planning is required in either

stator or rotor notching.

5. Also there has to be synchronous manufacturing between stator packetting and coil

manufacturing in winding shop and rotor notching and keyway milling operation in the

machine shop. Hence a signal kanban has to be send from stator notching or stator packetting

to the respective shops.

Based on the recommendations above the future state map (1LA0 254-4, 1LA0 284-4 and

1LA0314-4) is prepared.

44

Chapter 4

WINDING SHOP

The Stator packets from the press shop are the inputs to this shop and varnished

winding packets are the output to the assembly shop.

The operations in the winding shop are:

a. Coil Winding:

Coils are made on the coil forming machine. There are five machines which satisfy the

requirement of the entire plant.

b. Insulation Preparation:

At this workplace phase insulation papers are cut as per requirement. Motor type starting

from 1LA025 up to 1.875MW can be prepared at this workplace.

c. Stator Winding:

The coils prepared in the coil winding operation and the stator packets from the press shop

are the input to this operation. The coils are inserted into the packet as per the drawing made

on customer requirements. The finished stator packet is then send for the connection

operation

45

d. Connection:

Stator windings from the previous operation are the input for this operation. The phase

connections are done and the lead cables are connected as per the drawing from the design

department. After this the stator packet is sent for connection testing.

e. Impregnation:

Vacuum Pressure Impregnation (VPI) completely seals the windings against moisture and

vibration and provides greater mechanical strength. Stator winding after the connection

procedure is the input for this process. After impregnation the stator packet is sent for curing

in an oven and is then sent to assembly shop after scraping off the excess resin on the packet.

46

OBSERVATIONS

1. There are 5 coil winding machines, all capable of making all the types of coils. Setting time

contributes to 20% of total time. Also spool change time contributes to 5% of total time.

2. There are ten different types of wires of which six are used 97% of time.

3. In insulation cutting to, 22% of total time is setting time.

4. After stator winding the coil is sent to the connection station for phase connections because

all the worktables are not equipped with connection facilities. As a result there is WIP

inventory before the connection station.

5. Coil manufacturing starts only when the packet is ready and is released from the press shop.

Based on the observations made in the winding shop the current state map (1LA0 254-4,

1LA0284-4, 1LA0 316-4) is drawn:

50

RECOMMENDATIONS

1. In coil winding operation the coil winding machines to be standardized for making a coil for

a motor type and a particular size of copper wire. This will reduce the setup time by almost

70%.

2. Changeover from 90 kg to 180 kg size copper spools to improve machine utilization. Also as

the spool capacity has doubled the downtime of the machine will become half and would

hence save 200 to 300 SMH annually.

3. Also since the spool capacity is doubled the area for copper storage is reduced to half.

4. Synchronous manufacturing of coil and stator packet is recommended in order to save on the

additional lead time of coil manufacturing.

5. As Motor of frame size 25, 28, 31 four pole comprise of 75% to 80% of production the

insulation of this motors of every size to be cut and kept at least 10 in number. Also kanban

to be implemented for withdrawal of the insulation. As the quantity reduces to 5, a trigger

will be sent to refresh the insulation quantity to 10.

6. The operator doing the stator winding operation should also be trained in doing the

connection operation. Hence oxy-acetylene flame torches to be provided at every

workstation. This will also save 800 SMH per annum.

7. Pre heating of winding should be done with DC electric current. It will save about three hours

per job.

8. The curing of winding after impregnation to be done with DC electric current will save about

five hours per job.

Based on the recommendations made the future state map of the winding shop is as follows:

54

Chapter 5

MACHINE SHOP

The die cast or copper bar rotors from the press shop are the input to this shop and the

finished rotor is the output to the assembly shop.

The operations carried out in machine shop are:

a. Shaft centering facing and tapping:

The raw shaft from the vendor is loaded on the centering machine and the facing operation is

done first. The shaft is then sent for centering and after that the tapping is done to facilitate

easy lifting of shaft with help of eye bolt.

b. Shaft turning:

The shafts from the previous operation are the input to this operation. The shaft is loaded

between the centers and turned as per the drawing given by the design department. These

shafts are then sent for key way milling operation.

c. Keyway milling:

The shafts after the turning operation are sent to keyway milling operation. There is just one

machine for keyway milling which serves the need of entire plant. These shafts after keyway

milling are sent to the press shop.

d. Rotor turning:

Rotors from the press shop are the input to this operation. The die cast or the copper bar

inserted rotors are the input to this operation. The rotors are turned as per the specification in

the drawing, deburred. Post this operation red oxide is applied in order to prevent rust and

sent to grinding.

55

e. Shaft grinding:

After the rotor turning operation the rotor is sent for grinding. Parts where the pulley is fitted

on both the ends and also the keyway part is grinded to achieve the exact dimensions and

surface finish. Post this operation the rotor is sent to assembly line for motor assembly.

OBSERVATIONS

1. The lathe on which shaft is turned is placed on the other end of the gangway. As a result the

shaft coming into the shop has to travel through the gangway in order to reach the machine.

2. The lathes on which the die cast rotors from the press shop are turned are placed on the

entrance of the gangway. As a result the die cast rotors have to travel through the entire

gangway of either press shop or machine shop in order to reach the respective machine.

3. There is large amount of finished inventory kept in the shop which cannot be dispatched to

assembly because of unavailability of finished stator packets.

Based on the observation in the machine shop the current state map is drawn:

59

RECOMMENDATIONS

1. There has to be a single line flow between the turning and the grinding operation in order to

prevent and WIP in between the two operations.

2. The Becco lathe on which shafts are turned should be moved to the TSDC end of the

gangway in order to prevent the shaft to travel the whole gangway. This will save around 44

meters of material transport per shaft.

3. Similarly the die cast rotors from the TCS die casting machine are turned on two lathes, viz.

Rotor and Enterprise. These lathes to be moved from the start of the gangway to the winding

shop end. This will save around 74 meters of material transport per die cast rotor.

4. Also a passage, if possible is to be built between the TCS die casting machine and these two

lathes would reduce the material transport further by 34 meters.

5. The rotors are only to be finished i.e. deburring, grinding and applying antirust when the

respective stator packet goes for curing operation. This will reduce the finished goods

inventory in the machine shop. This would also prevent waiting for both the stator and the

rotor in the respective shop thus resulting to effective space utilization.

Based on the recommendations the future state map of the machine shop is as follows:

63

Chapter 6

ASSEMBLY SHOP

The final station in motor manufacturing process is the assembly shop. The shop gets input

from the winding shop (Stator Packet) and from the Rotor shop. Also there are a lot of

outsourced products such as end shield, bearing, motor housing etc from various vendors.

The operations carried out in assembly shop are:

a. Packet Pressing:

The finished stator packet from the winding shop and the motor housing from the outsourced

vendor are the input to this operation. The housing is loaded on the pressing machine and the

packet is pressed into it. This housing is then loaded on a separate table for terminal

connections.

b. Terminal Box Assembly:

The leads coming out of the stator packet are taken out from a terminal box and connected

and the necessary terminals are shot together. The input to the motor is given from the

terminal box and the output terminals (in case of the generators) are also taken from the box.

c. Auxiliary Terminal Box Assembly:

The additional features of a motor whose lead cables come out of the winding are connected

in a separate terminal box known as auxiliary terminal box. It includes the connections of

Anti Condensation Heater (ACH), Bearing Temperature Detector (BTD), Positive

Temperature Co-efficient (PTC), etc.

64

d. Rotor Balancing:

Rotor from the machine shop is the input to this operation. As a rotating machine the rotor

need to have even weight distribution on both the sides (to prevent vibrations) and is hence

balanced on a dynamic balancing machine. This rotor after balancing is then sent to the motor

assembly station for Bearing Assembly.

e. Bearing Assembly:

Balanced rotor is the input to this operation. The bearing assembly includes three parts on

either side of the rotor which are shrink fitted after induction heating for three hours at about

120°C. The bearing assembly consists of three parts viz.

i. Inner bearing cover

ii. Bearing

iii. Outer Bearing cover or Scavenging Disk (Done after Motor Assembly)

f. Motor Assembly:

The rotor with the bearing on each side is inserted into the stator housing and the end shields

are fitted on both ends of the shaft.

g. Fan Assembly:

This is the last operation in the motor manufacturing operation. The cooling fan is shrink

fitted on the B-side (non-output side) of the rotor in this operation. The fan cowl (fan cover)

is then fixed on this end above the fan.

65

OBSERVATIONS

1. There is a large amount of finished rotor inventory kept in the racks in the assembly shop.

2. The terminal boxes required on each motor is as per customer specification and hence a large

variety of terminal boxes are available.

3. The waiting time of components due to non-availability of specific required terminal box is

high

4. There is almost a 3 day WIP in the shop of Grade C items.

5. A large number of motors are waiting for acceptance testing from the customer.

Based on the observations the current state map is drawn:

69

RECOMMENDATIONS

1. The terminal box should be assembled offline and then directly fitted onto the motor.

2. One drilling machine should be procured in assembly shop such that standard terminal box

will be procured and non-standard drilling will be done in assembly as and when required.

This will reduce the waiting time for all the components consecutively.

3. A kanban system to be developed between assembly shop and machine shop to pull the

rotors from the shop when required and not stock inventory in the shop

4. Also a kanban system to be developed between the stores and the assembly shop in order to

control Grade C items inventory.

5. Motor assembly to be done only a day or two in advance of customers consent for motor

testing

Based on the recommendations the future state map is drawn.

73

Results

1. 600 SMH saved in press shop by the use of fixture for stator laminations during packetting

operation.

2. Standardizing the coil winding machine will also reduce the setup time by 70%.

3. Changeover from 90 kg to 180 kg copper spools saves about 3000 kg of copper scrap

annually, reduce the area required for copper storage to half the current area and gives SMH

rationalization of about 300 SMH annually by reducing the frequency of changing the

spools.

4. Keeping a buffer stock of insulation paper of 10 motors will save 800 SMH per annum.

5. Integration of winding and connection operation will save about 600 SMH annually.

6. Transportation of material reduced by 44 meters per shaft and 74 meters per die cast rotor

after changing the layout in the machine shop.

74

Bibliography

Learning to see

By Mike Rother & John Shook

The Lean Enterprise Memory Jogger

By Manor Parkway

Value Stream Mapping at Siemens Ltd

Documents

Transcript of Value Stream Mapping at Siemens Ltd