By : SK Muralee Tharan

LEAN

Lean is a concept based on fundamental principlesLean

Undeveloped Flow Developed Flow

A Developed Flow is Less DisruptiveLean Principle: Product flows through the manufacturing system

LEARNING OBJECTIVES

1• Value add

manufacturing

2 • Flow system manufacturing

3 • Cycle Time Reduction

4 • Waste Reduction

5 • Inventory and Space Reduction

6• Link of Supply Chain

Management to Lean

Meets high through put demands with very little inventory.

Doing more & more with less and less resources.

It is a concept of continuousimprovement.

It is increasing value by eliminatingWaste and slack resources.

Accommodating the shifting demand in any combination of products immediately.INTRODUCTION

New Business Sustainable Profits

DecreasedCost =

ImprovedFlow

DecreasedCost =

Eliminationof Waste

ImprovedFlow =

EVOLUTION OF MANUFACTURINGCraft

Mass

Made to customer spec.

Single-piece mfg

Variable quality

Little inventory

High cost

Interchangeable

parts Division of labor

(Taylor sys) Variable quality

Little inventory

High cost

Lean

High Variety Small batches PPM quality

Engaged workforce

1857 1900 1925 1950 1975 2000

LOT (MASS) PROD VS LEAN PROD

Lot (Mass) Prod

Floor layout is job-shop type.

Grouping machines of same type together.

Large lot product.

Machine used at large

Inventory is easy to accumulate between processes.

Single-process handling.

Workers are sitting while working.

Workers are single-skilled.

Insp. at the final stage process.

LEAN LAYOUT

Reduce movement of people

and material

Movement

is waste

Inbound

Outbound

LEAN OBJECTIVES

Queues eliminated. Immediate

feedback & better quality

Moveable or changeable machines.

Worker cross-training

Little space for inventoryShort distances

Delivery directly to work areas

Work cells for product families.

Effects of Automation &

Focussed Factory

LEAN LAYOUT

Companies are cutting inventories

by 90%

Improving on-time

delivery to >98%.

Reducing lead time

from months to

days.

Reducing waste/scrap/rework from 60%

to 80%

Reducing manufacturing space from 30% to 60%.

Increasing value to

customers.

LEAN REVOLUTION

MAPPING VALUE STREAM

Information Flow

Material Flow

Inventory (WIP)

Nonvalue-added activitiesTransportation flow

Define all activities required to design, order, and provide a specific product, from concept launch, from order to delivery, from raw material into the hands of the customer.THIS INCLUDES :

VALUE ADDING

Any operation or activity that changes, converts , or transforms material into the product that is sold to the customer.

NON-VALUE ADDING

Any operation that takes time and resources but does not add value to

the product sold to the customer.

NON-VALUE ADDING ACTIVITY

Value adding , 5%

Defects/Spoilage

Waiting

Rework / InspectOver/Under Early/Late

Production

Downtime (Changeovers)

Storage Inventory

Inspection

WASTE VS VALUE ADDED PRINCIPLES

The major problem within industries today is Waste.

One way of identifying waste is to check whether your operation (or activity) add any value to the product or service.

Waste is defined by Mr.Fujio Cho (Toyoto Company,Japan) as “Anything other than the minimum amount of equipment,materials,parts,space, add worker’s time,which are absolutely essential to add value to the product.

SUPPLY CHAIN MANAGEMENT-FRAMEWORK

DesignSupplierPurch & Stores

Manufacturing

Marketing

Customer

Material Flow

Information Flow

LEAN TOOLS

Flow System

Pull SystemQuick

Changeover

Mistake Proofing

Line Balancing

FLOW SYSTEM

Identify Value Stream

Focus on actual object –specific design, specific order or product itself from beginning to completion.

Ignore the traditional boundaries of jobs, careers and functions to remove impediments to continuous flow.

Rethink specific work practices to eliminate backflows, scrap and stoppage.

FLOW PRECONDITIONS

• They must always be in proper condition to run precisely.

• TPM• Quick changeover

Every machine must be

completely capable

• Cross-skilled in every task.• Poka-Yoke• Visual Controls (5S)

Every worker must be

completely capable.

• Start with one less at a time.Small batch or

single piece production.

PHYSICAL DESIGN

Operations are in close physical proximity

Products see same or similar sequence of operations.

Operations are interdependent.- All run to the drumbeat

- Drumbeat is customer demand.Space is minimized, room for

inventory is minimized.

Machines are located for easy maintenance.

Product flow is unidirectional. Often ‘U’ or ‘L’ shaped.

There is low variability (throughput and quality)

FLOW - PROXIMITY

Geographically concentrate

equipment to perform operations

into a “Cell” or “Line.”

FLOW-SEQUENCE

Design the process and cell so that products are made in the same sequence of operations.

-Simplifies cell operation-Minimizes WIP

FLOW INTERDEPENDENCE

Make operations interdependent..must be run to the same “Takt” time…no independent machine operation.• Synchronizes production• Highlights to the bottleneck• Removes queues between operations

~ Reduce cycle ~ Immediate quality feedback

THE PULL SYSTEM

• No one in upstream should produce until the customer downstream asks for it.

• Work backwards – pull the flow of value.

• Based on the idea of replenishment

• Linked to actual demand events

• The “Pull” is the schedule—all production and supply is replenishment-based.

KANBANIn a lean enterprise, it is a signal, sometimes, but not always, a card, authorizing production or delivery of required material and is initiated by consumption.

Definitions

Internal Kanban (move card)- Manual or electronic* Circulated between the using cell and the supplying work cell to authorize or replenishment.

Kanban Varieties

* Supplier Kanban- May be manual or electronic- phone, fax, EDI, internet* Circulated between the using work cell and the supplier to authorize movement or replenishment

Supplier Kanban

-Kanban Order Quantity • The Kanban lot size divided by

the kanban container quantity.

Kanban Calculation

Specific amount of inventory keeps on store shelves based on the past purchase patterns & expected future demand.

Customer come pull items they want off the shelves.

Supermarket clerk periodically looks what has been taken off from shelves & replenish.

The clerk, she directly ordering goods from the manufacturer.

Clerk draws from supermarket inventory but small amount.

Controlled amount of inventory using for replenishment.

PULL SYSTEMSUPERMARKET

PUSH High Inventory

Retailer Delivery

House

Refrigerator

Daily Product (Eggs , Milk,

Butter) that you need in a week.

Days not sure when ( Mon or Friday).

If you go vacation, all product spoilt.

Full- 2nd refrigerator

& garage

Wireless with button for each daily goods.

When you open new cartons of eggs of daily goods.

The next day they will deliver one unit to replenish.

Mean you have a small buffer.

If those product use a lot.

Trigger signal get into internet / phone & immediately deliver (JIT)

You receive only when you order.

Retailer receives product based on customer order.

PULL

Safety Stock

Buffer

MEET custome

r order

.

Internet upgrade

AVOID

inventory

SMALL

inventory

THE “SUPERMARKET”•A group of products or materials which is stored to respond to instantaneous demand.•Supermarket stock levels are determined through an understanding of typical demand patterns, service policy, and the time it takes to replenish stock.•Also known as Strategic Inventory.

“SUPERMARKET” KANBAN•A strategic inventory approach, which creates a buffer of planned inventory after an operation to mitigate lead-time and potential capacity constraints.•A variation of a min/max approach, this approach would typically include a Kanban signaling device back to the prior operation.

QUICK CHANGEOVER

Quick Changeover(Shorter setup time)

Reduces the need for inventory.

Gives more production flexibility

Enables a faster response to customer needs

CLASSIFICATION OF SETUP OPERATIONS • Classify setup operations into waste, internal setups (IED), and external setups (OED). - Waste – operation which do not add values to the setup. - Internal Setups – Operation that can only be performed while the machine is shut down. - External Setups – Operation that can be performed without shutting down the machine.* Eliminate the waste

INTERNAL SET UPS • Convert as many internal setups as possible to external setups. - Use standard insert module.•Improve internal setups (include adjustment). - Use specifically designed cart to organize tools. - Use quick-release fasteners instead of bolts and nuts.

Speed and flexibility enables ‘pull’ Satisfy demand quickly, replenish quickly

Shorter set-up time

Smaller batches

Shorter replenishment

time

Lower strategic inventory

Shorter lead time , lower inventory, high on-time delivery

= ==

SUM

….and It’s ‘Lean’

MISTAKE PROOFING (POKA-YOKE)

A process improvement Technology that prevents the production of faulty products

and avoids the costs related to the disposition and tracking of

defects.

WHY MISTAKE- PROOFING

a. To establish smooth flow productionb. To enable pull system to work.c. Improve qualityd. Reduce cycle time.e. Reduce cost of manufacturing.

THE FOUR ELEMENTS OF ZQC

It uses source inspection to catch errors before they become defects.

It uses 100 percent inspection to check all of products, not just a sample.

Because smart people do make mistakes, ZQC uses poka-yoke (mistake proofing) devices on processing or assembly equipment to carry out the checking function.

1

2

3

4

TYPES OF MISTAKE PROOFING DEVICES

1. Guide / reference / interference rod or pin

2. Template3. Limit switch /microswitch4. Counter5. Odd-part-out method6. Sequence restriction7. Standardize and solve8. Critical condition indicator9. Detect delivery chute10.Stopper / gate11.Sensor12.Mistake proof your mistake proofing

device :- Eliminate the condition- Redesign for symmetry- Redesign for asymmetry

LINE BALANCING

The allocation of resources (people and machinery) to accomplish a series of tasks

which minimizes the amount of idle time per resources for

a given production volume and time period.

LEAN STRATEGY

V alue Maping

Identify highest value

Apply Lean Tools- Flow system- Pull system- Quick changeover and T P M- Mistake proofing and visual control- Line balancing and takt time