slide show week #9 chapter 11 jit

©The McGraw-Hill Companies, Inc., 2004

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Chapter 11

Just-in-Time and Lean Systems

MANAGEMENT 520

CHAPTER 11

JUST IN TIME

AND LEAN SYSTEMS


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• JIT Defined

• The Toyota Production System

• JIT Implementation Requirements

• JIT in Services

LESSON OBJECTIVES


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Just-In-Time (JIT)Defined

• JIT can be defined as an integrated set of activities designed to achieve high-volume production using minimal inventories (raw materials, work in process, and finished goods)

• JIT also involves the elimination of waste in production effort

• JIT also involves the timing of production resources (i.e., parts arrive at the next workstation “just in time”)


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JIT and Lean Management• JIT can be divided into two terms: “Big JIT”

and “Little JIT”• Big JIT (also called Lean Management) is a

philosophy of operations management that seeks to eliminate waste in all aspects of a firm’s production activities: human relations, vendor relations, technology, and the management of materials and inventory

• Little JIT focuses more narrowly on scheduling goods inventory and providing service resources where and when needed


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JIT Demand-Pull Logic

Customers

Sub

Sub

Fab

Fab

Fab

Fab

Vendor

Vendor

Vendor

Vendor

Final Assembly

Here the customer starts the process, pulling an inventory item from Final Assembly…

Here the customer starts the process, pulling an inventory item from Final Assembly…

Then sub-assembly work is pulled forward by that demand…

Then sub-assembly work is pulled forward by that demand…

The process continues throughout the entire production process and supply chain

The process continues throughout the entire production process and supply chain


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The Toyota Production System

• Based on two philosophies:

• 1. Elimination of waste

• 2. Respect for people

Toyota’s run smoother than this!


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Waste in Operations

1. Waste from overproduction

2. Waste of waiting time

3. Transportation waste

4. Inventory waste

5. Processing waste

6. Waste of motion

7. Waste from product defects


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Minimizing Waste: Focused Factory

Networks

CoordinationSystem Integration

These are small specialized plants that limit the range of products produced (sometimes only one type of product for an entire facility)

These are small specialized plants that limit the range of products produced (sometimes only one type of product for an entire facility)

Some plants in Japan have as few as 30 and as many as 1000 employees

Some plants in Japan have as few as 30 and as many as 1000 employees


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Minimizing Waste: Group Technology (Part 1)

• Using Departmental Specialization for plant layout can cause a lot of

unnecessary material movement • Using Departmental Specialization for plant layout can cause a lot of

unnecessary material movement

Saw Saw

Lathe PressPress

Grinder

LatheLathe

Saw

Press

Heat Treat

Grinder

Note how the flow lines are going back and forthNote how the flow lines are going back and forth


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Minimizing Waste: Group Technology (Part 2)

• Revising by using Group Technology Cells can reduce movement and improve product flow

• Revising by using Group Technology Cells can reduce movement and improve product flow

Press

Lathe

Grinder

Grinder

A

2

BSaw

Heat Treat

LatheSaw Lathe

PressLathe

1


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Minimizing Waste: Uniform Plant Loading (heijunka)

Not uniform Jan. Units Feb. Units Mar. Units Total

1,200 3,500 4,300 9,000

Uniform Jan. Units Feb. Units Mar. Units Total

3,000 3,000 3,000 9,000

Suppose we operate a production plant that produces a single product. The schedule of production for this product could be accomplished using either of the two plant loading schedules below.

Suppose we operate a production plant that produces a single product. The schedule of production for this product could be accomplished using either of the two plant loading schedules below.

How does the uniform loading help save labor costs?How does the uniform loading help save labor costs?

or


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Minimizing Waste: Just-In-Time Production

• Management philosophy• “Pull” system though the plant• Hydraulic Push Systems

WHAT IT IS

• Employee participation• Industrial engineering/basics• Continuing improvement• Total quality control• Small lot sizes

WHAT IT REQUIRES

• Attacks waste• Exposes problems and bottlenecks• Achieves streamlined production

WHAT IT DOES

• Stable environment

WHAT IT ASSUMES


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Minimizing Waste: Inventory Hides Problems

Work in

process

queues

(banks)

Change

orders

Engineering design

redundancies

Vendor

delinquencies

Scrap

Design

backlogs

Machine

downtime

Decision

backlogsInspection

backlogs

Paperwork

backlog

Example: By identifying defective items from a vendor early in the production process the downstream work is saved

Example: By identifying defective work by employees upstream, the downstream work is saved


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Minimizing Waste: Kanban Production Control Systems

Storage Part A

Storage Part AMachine

Center Assembly Line

Material Flow

Card (signal) Flow

Withdrawal kanban

Once the Production kanban is received, the Machine Center produces a unit to replace the one taken by the Assembly Line people in the first place

This puts the system back were it was before the item was pulled

The process begins by the Assembly Line people pulling Part A from Storage

Production kanban


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Determining the Number of Kanbans Needed

• Setting up a kanban system requires determining the number of kanbans cards (or containers) needed

• Each container represents the minimum production lot size

• An accurate estimate of the lead time required to produce a container is key to determining how many kanbans are required

• Side Bar – In Japan space is a very important consideration since there is so little of it. This process saves on space requirements. May explain why concept NIH.


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Example of Kanban Card Determination: Problem Data

• A switch assembly is assembled in batches of 4 units from an “upstream” assembly area and delivered in a special container to a “downstream” control-panel assembly operation

• The control-panel assembly area requires 5 switch assemblies per hour

• The switch assembly area can produce a container of switch assemblies in 2 hours

• Safety stock has been set at 10% of needed inventory


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Example of Kanban Card Determination: Calculations

3or ,75.24

5(2)(1.1))(1

container theof Size

stockSafety timelead during demand Expected

C

SDL

k

3or ,75.24

5(2)(1.1))(1

container theof Size

stockSafety timelead during demand Expected

C

SDL

k

Always round up!


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Respect for People

• Level payrolls

• Cooperative employee unions

• Reliable Subcontractor networks

• Bottom-round management style (i.e., consensus management)

• Quality circles (Small Group Involvement Activities or SGIA’s)


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Toyota Production System’s Four Rules

1. All work shall be highly specified as to content, sequence, timing, and outcome

2. Every customer-supplier connection must be direct, and there must be an unambiguous yes-or-no way to send requests and receive responses

3. The pathway for every product and service must be simple and direct

4. Any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization


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JIT Implementation Requirements: Design Flow Process

• Link operations

• Balance workstation capacities

• Redesign layout for optimum flow

• Emphasize preventive maintenance

• Reduce lot sizes

• Reduce setup/changeover time


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JIT Implementation Requirements: Total Quality Control

• Worker responsibility

• SQC in place

• Enforce compliance

• Fail-safe methods (poka-yokes)


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JIT Implementation Requirements: Stabilize Schedule

• Level schedule

• Underutilize capacity

* Freeze Window (schedule is fixed an no changes permitted)


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JIT Implementation Requirements: Kanban-Pull

• Demand pull

• Backflush (periodically explode a BOM to determine what items went into the product

• Reduce lot sizes


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JIT Implementation Requirements: Work with Vendors

• Reduce lead times

• Frequent deliveries

• Project usage requirements

• Clear Quality expectations


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JIT Implementation Requirements: Reduce Inventory More

• Look for other areas to reduced materials

• Minimize Stores

• Minimize Transit

• Carousels

• Conveyors


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JIT Implementation Requirements: Improve Product Design

• Standard product configuration

• Standardize and reduce number of parts

• Align Process design with product design

• Quality expectations


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JIT Implementation Requirements: Concurrently Solve Problems

• Root cause • Solve problems permanently

• Team approach

• Line and specialist responsibility

• Continual education


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JIT Implementation Requirements: Measure Performance

• Emphasize improvement

• Track trends


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JIT in Services (Examples)

• Organize Problem-Solving Groups

• Upgrade Housekeeping

• Upgrade Quality

• Clarify Process Flows

• Revise Equipment and Process Technologies


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JIT in Services (Examples)

• Level the Facility Load

• Eliminate Unnecessary Activities

• Reorganize Physical Configuration

• Introduce Demand-Pull Scheduling

• Develop Supplier Networks


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Question BowlJust-In-Time seeks to achieve high volume

production using what three approaches: (5 points each item)

a. Minimal inventory of r-- m--------

b. Minimal inventory of w--- i- p------

c. Minimal inventory of f------- g----

Answer: raw materials, work in process, finished goods.


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Question BowlLean Management is closely associated

with which of the following? (5 points)

a. Big JIT

b. Little JIT

c. Honda Motor Company

d. McDonald’s low carb menu item

e. The Atkins Diet

Answer: a. Big JIT


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Question BowlIn the Toyota Production System, the

“elimination of waste” involves: (5 points for each item):

1. O-------------

a. W------ T---

b. T-------------

Answer: overproduction, wasting time, transportation


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Question BowlIn the JIT Pull System the partner that

begins the process of “pulling” is which of the following? (5 points)

a. Customers

b. Vendors

c. Fabrication personnel

d. CEO

e. All of the aboveAnswer: a. Customer


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Question BowlA JIT Production program requires: (5

points each item)

1. E------- P-----------

a. T----- Q------ C------

b. S----- l– s----

c. C--------- i----------

Answer: Employee participation, Total Quality Control, Small lot sizes, continuous improvement


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Question BowlInventory has been known to hide the

following production problems? (5 points each item)

a. S----

b. V----- d------------

c. D------- b--------

Answer: Scrap, Vendor delinquencies, decision backlogs


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Question BowlYou want to determine how many kanban card sets you

need for an operation. You find that average number of units demanded is 1,000 per hour, the lead time to replenish the order for this item is 10 hours, the container size is 10 units, and the safety stock is estimated to be 5% of the expected demand. Which of the following is the desired number of kanban card sets? (15 points)

a. 1050

b. 1000

c. 605

d. 500

e. None of the above

Answer: a. 1050 ([1000x10](1+0.05)/10=1050)


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Question BowlWhen trying to implement JIT a “stabilized

schedule” includes which of the following? (5 points)

a. Demand pull

b. Backflush

c. Fail-safe methods

d. All of the above

e. None of the above

Answer: e. None of the above (These include: level schedule, underutilization capacity, and establish freeze windows.)

slide show week #9 chapter 11 jit

Business

operations waste

elimination of waste

production plant

overproduction waste

highvolume production

streamlined production

schedule of production

storage production kanban