Japansk produktionsfilosofi- lean manufacturing

Johann Packendorff

Definition of “Lean”

• Half the hours of human effort in the factory

• Half the defects in the finished product

• One-third the hours of engineering effort

• Half the factory space for the same output

• A tenth or less of in-process inventories

Source: The Machine that Changed the World Womack, Jones, Roos 1990

Lean Manufacturing is a manufacturing philosophy which shortens the time line between the

customer order and the product shipment by eliminating waste.

CustomerOrder

Waste ProductShipment

Time

CustomerOrder

ProductShipment

Time (Shorter)

Business as Usual

Waste

Lean Manufacturing

APICS Definition of Lean Manufacturing

“A philosophy of production that emphasizes the minimization of the amount of all the resources (including time) used in the various activities of the enterprise. It involves:

– … identifying and eliminating non-value-adding activities,

– … employing teams of multi-skilled workers,

– … using highly flexible, automated machines”

• American Production and Inventory Control Society (APICS) is an organization for professionals working in the field of Operations Management

New Paradigm: Non-Blaming CultureManagement creates a culture where:

• Problems are recognized as opportunities

• It’s okay to make legitimate mistakes

• Problems are exposed because of increased trust

• People are not problems - they are problem solvers

• Emphasis is placed on finding solutions instead of “who did it”

SOLUTIONSPROBLEMS

What makes a manufacturing system Lean?

What makes a manufacturing system Lean?

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5S Programs

• Seiri (sort, necessary items)

• Seiton (set-in-order, efficient placement)

• Seison (sweep, cleanliness)

• Seiketsu (standardize, cont. improvement)

• Shitsuke (sustain, discipline)

• “Ability to understand the status of a production area in 5 minutes or less by simple observation without use of computers or speaking to anyone.”

• 5-S– 1S Sift and Sort (Organize)– 2S Stabilize (Orderliness)– 3S Shine (Cleanliness)– 4S Standardize (Adherence)– 5S Sustain (Self-discipline)

Visual Factory

What makes a manufacturing system Lean?

The Pull System

Kanban Production Control• At the core of JIT manufacturing at Toyota is

Kanban, an amazingly simple system of planning and controlling production

• Kanban, in Japanese, means card or marquee

• Kanban is the means of signaling to the upstream workstation that the downstream workstation is ready for the upstream workstation to produce another batch of parts

Kanbans and Other Signals

• There are two types of Kanban cards:– a withdrawal card (W-Kanban)– a production card (P-Kanban)

• Signals come in many forms other than cards, including:– an empty crate– an empty designated location on the floor

How Kanban Operates

When a worker at downstream Work Center #2 needs acontainer of parts, she does the following:

– She takes the W-Kanban from the container she just emptied

– She finds a full container of the needed part in storage– She places the W-Kanban in the full container and

removes the P-Kanban from the full container and places it on a post at Work Center #1

– She takes the full container of parts with its W-Kanban back to Work Center #2

Kanban CardsWithdrawal Kanban CardWithdrawal Kanban Card

Part number to produce: Part number to produce: M471-36M471-36 Part description: Part description: Valve HousingValve Housing

Lot size needed: Lot size needed: 4040 Container type: Container type: RED CrateRED Crate

Card number: Card number: 2 of 52 of 5 Retrieval storage location: Retrieval storage location: NW53DNW53D

From work center: From work center: 2222 To work center: To work center: 3535

Kanban CardsProduction Kanban CardProduction Kanban Card

Part number to produce: Part number to produce: M471-36M471-36 Part description: Part description: Valve HousingValve Housing

Lot size needed: Lot size needed: 4040 Container type: Container type: RED crateRED crate

Card number: Card number: 4 of 54 of 5 Completed storage location: Completed storage location: NW53DNW53D

From work center: From work center: 2222 To work center: To work center: 3535

Materials required:Materials required:Material no. Material no. 744B744B Storage location: Storage location: NW48CNW48CPart no. Part no. B238-5B238-5 Storage location: Storage location: NW47BNW47B

Flow of Kanban Cards and Containers

UpstreamUpstreamWork Center #1Work Center #1

DownstreamDownstreamWork Center #2Work Center #2

In-processIn-processstoragestorage

Parts FlowParts Flow

P-Kanban andP-Kanban andempty containerempty container

Full containerFull containerand P-Kanbanand P-Kanban

W-Kanban andW-Kanban andempty containerempty container

Full containerFull containerand W-Kanbanand W-Kanban

Containers in a Kanban System

• Kanban is based on the simple idea of replacement of containers of parts, one at a time.

• Containers are reserved for specific parts, are purposely kept small, and always contain the same standard number of parts for each part number.

• At Toyota the containers must not hold more than about 10% of a day’s requirements.

• There is a minimum of two containers for each part number, one at the upstream “producing” work center and one at the downstream “using” work center.

What makes a manufacturing system Lean?

Reducing Inventoriesthrough Setup Time Reduction

• Central to JIT is the reduction of production lot sizes so that inventory levels are reduced.

• Smaller lot sizes result in more machine setups

• More machine setups, if they are lengthy, result in:

– Increased production costs

– Lost capacity (idle machines during setup)

• The answer is: REDUCE MACHINE SETUP TIMES

SMED-metoden

1. Mät hela omstället och identifiera alla enskilda moment i omstället.

2. Bestäm vilka steg som kan utföras innan- och efter att maskinen måste stannas (ej producerar). Dessa steg benämns externa steg.

3. Minska tiden maskinen måste stå stilla genom att flytta de externa stegen innan- och efter maskinen står stilla.

4. Förbättra verktyg, jiggar detaljer i maskinen samt arbetssätt för att förbättra de steg som bara kan utföras när maskinen står stilla, interna steg.

5. Förbättra de externa stegen.

6. Skriv ned de nya standarderna i arbetsinstruktioner och försäkra att att alla arbetar enligt det nya arbetssättet.

What makes a manufacturing system Lean?

Effective Facility Layouts

• Workstations in close physical proximity to reduce transport & movement

• Streamlined flow of material

• Often use:– Cellular Manufacturing (instead of process focus)– U-shaped lines: (allows material handler to quickly

drop off materials & pick up finished work)

Traditional Process Focused Layout

• Jumbled flows, long cycles, difficult to schedule

JIT Cellular Manufacturing

• Product focused cells, flexible equipment, high visibility, easy to schedule, short cycles

What makes a manufacturing system Lean?

INTRODUCTION INTRODUCTION Total Productive Maintenance (TPM) is an

approach to managing physical assets that emphasizes the importance of operator involvement in making equipment reliable

Management has always held an operator accountable for production output. More than ever, that person is also responsible now for product quality

Many factors affect how well that can be achieved, including the way in which the workplace is organized as well as the equipment’s effectiveness. When several people are involved, producing quality depends on teamwork

In its broadest sense, TPM is based on the idea of autonomous operator maintenance, including three sets of principles. Maintenance Engineering; Seeks to manage the equipment

life cycle, from strategic asset planning, through design and construction, to operation, maintenance, and disposal. Several techniques characterize the proactive nature of maintenance engineering including:

Preventive (or planned) maintenance: Planned and scheduled maintenance activities to find and correct problems that could lead to failure

Predictive and condition-based maintenance: Reducing fixed-time maintenance and relying on the condition of equipment to determine maintenance activity

The prime objectives of TPM are to: Maximize equipment effectiveness and productivity and

eliminate all machine losses Create a sense of ownership in equipment operators

through a program of training and involvement Promote continuous improvement through small-group

activities involving production, engineering, and maintenance personnel

Each enterprise has its own unique definition and vision for TPM, but in most cases there are common elements in any TPM program. These have been summarized in the TPM wheel in Figure 8-1

ThemesThemes

• TrainingTraining

• DecentralizationDecentralization

• Maintenance Maintenance preventionprevention

• Multi-skillingMulti-skilling

ElementsElements

Figure 8-1 The TPM WheelFigure 8-1 The TPM Wheel

Asset Asset

StrategyStrategy

Continuous Continuous

ImprovementImprovement

TeamTeam

ProcessesProcesses

EmpowermentEmpowerment

Resources Resources

Planning andPlanning and

SchedulingScheduling

Systems andSystems and

ProceduresProcedures

MeasurementMeasurement

TPM puts the power in the employee’s hand. It grants workers autonomy, along with responsibility

At the same time TPM recognizes that employees in one area have much to teach and learn from others The entire organization gains strength and ideas from motivated continuous improvement teams

A TPM environment encourages a skills between operators and maintenance, and multi-skill training in the various crafts

It can provide increase job satisfaction for operations, trades, engineering, and supervision alike

For Problem Definition For Solution Development For Team Decision-making

• Process flowcharting • Customer surveys • Consequences seeking

• Histograms •Cause and effect diagrams • Brainstorming

• Plan charts • Benchmarking • Normal group technique

• Tree diagrams • Force field analysis • Multivoting

• Pareto diagrams • FMECA • Pairwise ranking

• Statistical process control • Fault tree analysis • Weighted factor evaluation

• Scatter plots • P-M analysis

• Failure Analysis

Automated Tools

• Computer aided design and drafting

• Computer aided manufacturing

• Computerize maintenance management system

• Material management system

• Materials equipment planning

• Computer integrated manufacturing

• Simulation

• Expert systems

• Geographic information management system

Figure 8-4 Tools and Techniques for TPMFigure 8-4 Tools and Techniques for TPM

What makes a manufacturing system Lean?

• "Value" is what the customer is buying

• Always think first about the end-customer– Who is the customer?– What are they buying?

• Describe value using the customers' words

What Is Value?

Planning tool to optimize results of eliminating waste

What Is Value Stream Analysis?

+ + =LeanBasics

current state VSM future state VSM

Value Steam Mapping Steps

Current State

Future State

Next Future State

Original State

Value Stream Scope

Extended Value StreamExtended Value StreamConceptConcept LaunchLaunchOrderOrder DeliveryDeliveryIn-useIn-use RecycleRecycle

Action Action

Multi-plant/Multi-companyMulti-plant/Multi-company

ActionAction

PlantPlant

Action ActionAction

Apply Five Simple Principles:

Specify value from the standpoint of end customer

Identify the value stream for each product family

Make the product flow

So the customer can pull

As you manage toward perfection

Perfection

PULL FLOW

VALUE STREAM

VALUE

What is the Value that Flows?Specify value from the standpoint of the end customer

Ask how your current products and processes disappoint your customer’s value expectation:

price?

quality?

reliable delivery?

rapid response to changing needs?

???

"ITEMS" flow through a value stream– In manufacturing, materials are the items– In design & development, designs are the items– In service, external customer needs are the items– In admin., Internal customer needs are the items

Analysis begins with part of a total value stream,

That part of the value stream has customers too

What Flows?

Material Flow Icons

First-In-First-Out Sequence Flow

FIFOmax. 20 pieces

Manufacturing Process

ASSEMBLY

Finished Goods to Customer

Truck Shipment

Mon.+ Wed.

Outside Sources

XYZ Corporation

Data Box

C/T = 45 sec.

C/O = 30 min.

3 Shifts

2% Scrap

PUSH Arrow

300 pieces1 DaySupermarket

Inventory

Physical Pull/Withdrawa

l

Buffer or Safety Stock

Information Flow Icons

Manual Information

Flow

Electronic Information

Flow

Kanban Post

Withdrawal Kanban

Production Kanban

Sequenced-Pull Ball

“Go See” Production Scheduling

Signal Kanban

Load Leveling Box

Schedule

WeeklySchedule

General Icons

KaizenLightening Burst

UPTIME

CHANGEOVER

Operator

TAKT TIME

Effective Working Time per Shift

Customer Requirement per Shift

Takt Time =

Synchronizes pace, evenly applying customer demand across the work day.

Takt Time is "Beat Time"? "Rate Time" or “Heart Beat" Lean Production uses Takt Time as the rate or time that a completed product is finished. If you have a Takt Time of two minutes that means every two minutes a complete product, assembly or machine is

produced off the line. (http://www.isixsigma.com/dictionary/Takt_Time-455.htm)

Implementing lean

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Benefits of Lean Manufacturing

• 50 - 80% Waste reduction– WIP– Inventory– Space– Personnel– Product lead times– Travel– Quality, costs, delivery

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Setting the Foundation

• Evaluating your organization– Management culture

– Manufacturing culture

• Lean Manufacturing Analysis– Value stream (from customer prospective)

– Headcount

– WIP

– Inventory

– Capacity, new business, supply chain

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Tools of Lean Mfg/Production

• Waste reduction – Full involvement, training, learning– Cellular mfg– Flexible mfg– Kaikaku (radical change)– Kaizen (continuous improvement) & standard work– 5S– Jidoka (autonomation)– Poka-yoke (visual signals)– Shojinka (dynamic optimization of # of workers)– Teien systems (worker suggestions)

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Tools (cont.)

• Continuous Flow (10% - 25%)– SMED (Shingo)– Andon– Takt time– Line balancing– Nagara (smooth production flow)

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Tools (cont.)

• Customer pull (10%- 25%)– Just-in-time– Kanban

Henry Ford - Standards“To standardize a method is to choose out of the many

methods the best one, and use it. Standardization means nothing unless it means standardizing upward.

Today’s standardization, instead of being a barricade against improvement, is the necessary foundation on which tomorrow’s improvement will be based.

If you think of “standardization” as the best that you know today, but which is to be improved tomorrow - you get somewhere. But if you think of standards as confining, then progress stops.”

Henry Ford, 1926

Today & Tomorrow

• Captures best practices• Posted at the work station• Visual aid• Reference document

– work sequence– job layout– time elements– safety

• Developed with operators• Basis for Continuous Improvement

Standardized Work

• Visual Factory

• Error Proofing

• Quick Change-over

• Total Productive Maintenance

Other Tools

What makes a manufacturing system Lean?