TÀI LIỆU ÔN THI QTSX Toyota Production System and Lean Manufacturing

Effectiveness is the result of the integration of: -Man -Method -Material -Machine At the worksite •Waste exists in all work and at all levels in the organization Identification and Elim

Trang 1

Toyota Production System

and Lean Manufacturing

D Jorge Leon Texas A&M University

TOYOTA PRODUCTION SYSTEM

The Toyota Production System was adopted by

many Japanese companies in the aftermath of the

1973 oil shock

“Waste” Elimination Philosophy:

“ Above all, one of our most important purposes was increased

productivity and reduced cost To achieve this purpose, we put our

emphasis on the notion of eliminating all kinds of unnecessary

functions in the factories Our approach has been to investigate one by

one the causes of various "unnecessaries" in manufacturing operations

and to devise methods for their solution, often by trial and error ”

Trang 2

PURPOSES OF JIT

Primary Purpose:

Profit through cost reduction (or improvement of

Productivity) This is attained through WASTE elimination.

Other important purposes:

Quantity control:

JIT, Kanban & Autonomation (visual control system)

Quality control:

Autonomation, improvement by small groups, functional

management

Respect for humanity :

Flexible work force (adapt to demand changes), capitalize

workers ideas

TYPES OF WASTE

Excessive production resources(primary waste):

excessive workforce excessive facilities excessive inventories unnecessary capital investment

Overproduction(secondary waste - the WORST waste):

leads to

Excessive inventories(tertiary waste):

extra jobs make overproduction invisible.

adds losses in opportunity cost

lead to

Unnecessary capital investment(fourth waste):

Trang 3

TO ACHIEVE THESE PUPOSES

7 Wastes Elimination Just-In-Time (JIT) Production

Kanban System Production Smoothing

5S Setup Time Reduction

Machine Layout & Multi-function Worker

Autonomation (Visual Management)

Trang 4

•Identification and elimination of waste is the central theme of a

lean manufacturing production system

•Lean manufacturing is a dynamic and constantly improving

process dependent upon understanding and involvement by all

employees

•Successful implementation requires that all employees must be

trained to identify and eliminate waste from their work

•Waste exists in all work and at all levels in

the organization

Identification and Elimination of Waste

Trang 5

Effectiveness is the result of the integration of:

-Man

-Method

-Material

-Machine

At the worksite

•Waste exists in all work and at all levels in the organization

Identification and Elimination of Waste

Seven Types of Waste

7 Wastes, Applied Material’s, Lean Manufcaturing, Supplier Copy, 1999.

Over-production Wait time

Transportation Processing Inventory Motion Defects

Trang 6

Over-production Waste

Definition

Producing more than needed

Producing faster than needed

Characteristics:

• Inventory Stockpiles

• Extra equipment/oversized equipment

• Unbalanced Material Flow

• Extra Part Storage racks

• Extra Manpower

• Batch Processing

• Complex Inventory Management

• Excessive Capacity/Investment

• Additional Floor Space/Outside Storage

• Hidden Problems

• Excessive Obsolescence

• Large Lot Sizes

• Building Ahead

Trang 7

•Incapable Processes

•Just in Case Reward System

•Lack of Communication

•Local Optimization

•Automation in the Wrong Places

•Cost Accounting Practices

•Low Uptimes

•Lack of Stable/Consitent Schedules

Waiting Time Waste

Definition

Idle Time That is Produced When Two Dependant Variables are

not Fully Synchronized

•Man Wait Time

•Machine Wait Time

Trang 8

•Man Waiting for Machine

•Machine/Materials Waiting for Man

•Unbalanced Operations (Work)

•Lack of Operator Concern for Equipment Breakdowns

•Unplanned Equipment Downtime

Waiting Time Waste

Causes:

•Inconsistent Work Methods

•Long Machine Change Over Time

•Low Man/Machine Effectiveness

•Lack of Proper Equipment/Materials

Trang 9

Transportation Waste

Definition

Any Material Movement That Does Not Directly Support a Lean

Manufacturing System

•Extra carts, fork lifts, dollies

•Multiple Storage Locations

•Extra Material Racks

•Complex Inventory Management

•Extra Facility Space

•Incorrect Inventory Counts

•Damaged Material

Trang 10

Causes:

•Large Lot Processing

•Unleveled Schedules

•Lack of 5 S’s

•Lack of Visual Controls

•Improper Facility Layout

•Large Buffers and In Process Kanbans

Processing Waste

Definition

Effort Which Adds No Value To a Product or Service

Enhancements which are Transparent to The Customers or

Work Which Could Be Combined with Another Process

Trang 11

•Process Bottlenecks

•Lack of Clear Customer Specifications

•Endless Refinement

•Redundant Approvals

•Extra Copies/Excessive Information

Causes:

•Engineering Changes Without Processing Changes

•Decision Making at Inappropriate Levels

•Inefficient Policies and Procedures

•Lack of Customer Input Concerning Requirements

Trang 12

Inventory Waste

Definition

Any Supply in Excess of Process Requirements Necessary to

Produce Goods or Services Just in Time

Inventory Waste

•Extra Space on Receiving Docks

•Material Between Processes

•Stagnated Material Flow

•LIFO instead of FIFO

•Extensive Rework When Problems Surface

•Long Lead Time for Engineering Changes

•Additional Material Handling Resources (Men, Equipment,

Racks, Storage Space)

Trang 13

Inventory Waste

Causes:

•Uncontrolled Bottleneck Processes

•Incapable Suppliers

•Long Change Over Times

•Management Decisions

•Local Optimization

•Inaccurate Forcasting Systems

Wait Time

Defects Process

Over Production

Inventory Level

Motion Waste

Definition

Any Movement of People Which Does Not Contribute Added

Value To The Product or Service

Trang 14

Motion Waste

•Looking for Tools

•Excessive Reaching or Bending

•Material Too Far Apart (Walk Time)

•Equipment for Moving Parts

•Extra “Busy” Movements While Waiting

Motion Waste

Causes:

•Equipment, Office & Plant Layout

•Lack of 5 S’s

•Lack of Visual Controls

•Inconsistent Work Methods (Standardized Work)

•Large Batch Sizes

Trang 15

Rework or Correction Waste

Definition

Repair of a Product or Service To Fulfill Customer requirements

•Extra Floor Space/Tools/Equipment

•Extra Manpower To Inspect/Rework/Repair

•Stockpiling Inventory

•Complex Material Flow

•Questionable Quality

•Missed Shipments/Deliveries

•Lower Profits Due To Scrap

•Reactive Organization

Trang 16

Causes:

•Excessive Variation

•Incapable Suppliers

•Management Decisions

•Insufficient Training

•Inadequate Tools/Equipment

•Poor Layouts/Unnecessary Handling

•High Inventory Levels

Over-production Wait time

Transportation Processing Inventory Motion Defects

Trang 17

Định dạng
Số trang	17
Dung lượng	1,05 MB