application of the 7 wastes on a production line …ntdung_ise/material/process...ldeming emphasised...

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Sam Berkhauer-Smith 2006

Application of The Seven Wastes on a Production Line

Process Improvement & Quality Engineering

Sam Berkhauer-Smith

[email protected]

Introduction

l What is Waste?l How to manage the Seven Wastes

& examplesl The New Wastesl How the Seven Wastes are

actually applied!l How the reduced and eliminate

them!

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Tools & Techniques

Allows ideas to be generated

Allows data to be gathered and

analysed

Depending on circumstances / process /

problem

Many Tools

Simulation

Design of Experiments

7 Wastes

5s

Six Sigma

Statistical Process Control

Process Control

Problem Solving

Data Analysis

What is a Waste?

The opposite to value

Products or services which require rectification or don’t meet the customers needs.

Production of an item no-one wants.

Goods stocked in piles everywhere.

Steps in process that aren’t actually needed.

Excessive movement of employees.

Transportation of goods from one place to another without purpose.

Waiting for materials, machines and people.

Muda

l Is Japanese for Wastel More powerful than the word Waste as it is

associated with the 7 Wastesl Taiichi Ohno originally assembled the wastesl He was the father of the Toyota production

system, of JIT & Lean Operationsl Deming emphasised waste reduction in

Japan in the 1950’s

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Types of Waste

Process Waste – e.g. C/O times, SPC, Planning, Evaluation etc. Currently they are necessary for the process, but do not add value. Aim reduce them and then eliminate.

Business Waste – e.g. it benefits managers, employees & suppliers. Again are waste. These have to be critically examined for efficiency or elimination.

Pure Waste – should be eliminated as soon as possible

Necessary but Non Value Added:Any work carried out, which is necessary under currentconditions, but does not increase product value e.g inspection, part movement,tool changing, maintenance, etc(Minimise)

Non Value Added Waste:All other meaningless, non-essential activities that don’t add value to the product (Minimise)

Value Added:Any process that changes the nature, shape or characteristicsof the product, in line with customer requirements e.g welding, assembly(Maximise)

Value Added, Non-Value Added and Waste

Non Value Added Activities -Waste

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Value Adding Activities!

The Seven Deadly Wastes

How to spot them and manage them.


l Original 7 wastes or “Muda” developed by Taiichi Ohno

l Productivity based, but quality linked

l “Waste” is the opposite to “Value Adding”

l Should be considered as a set

l Form the core of the “lean philosophy”

So, what are they?

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The 7 Wastes

What are the 7 WASTES?

1. Transport

2. Inventory

3. Motion

4. Waiting

5. Over Production

6. Over Processing

7. Defects

1. Transport

Why a Waste?:

( Increases production time( It consumes resource & floor

space( Poor communication( Increases work in progress( Potential damage to products

Caused by:

( Badly designed process/cell( Poor value stream flow( Complex material flows( Sharing of equipment

Transport

l Customers do not pay to have goods moved around

l Therefore, any movement of materials in a factory is waste

l Can’t be fully eliminated, but can be continually reduced

l Number of handling operations is proportional to risk of damage and deterioration

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Transport

l Closely linked to communication– Long distances = poor communication– Increased awareness that for improved quality

interacting groups need to be located closer together

– News of quality problems not fed back

l Once recognised, it can be addressed– Monitoring flow lengths through operations– Number of steps (esp. non value-adding steps)– Spaghetti diagram is very useful– Also look at customer movements

Transport

l Examples– Double handling– All movements by forklift– Conveyors

2. Inventory

Why a Waste?:

( Adds cost( Extra storage space required( Extra resource to manage( Hides shortages & defects( Can become damaged( Shelf life expires

Caused by:

( Production schedule not level

( Inaccurate forecasting( Excessive downtime/set up( Push instead of pull( Large batching( Unreliable suppliers

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Unnecessary Inventory

l Inventory is the enemy because:– It increases leadtime (>99% of WIP is actually

Work In Queue)– It ties up money that could be used to improve

processes– It prevents rapid identification of problems– It separates process steps and reduces

communication– Its’ true cost is much higher than the money tied

up in it


l Inventory hides problems by covering them up

– Quality problems seen as not important because there are always “spare” parts

– Process reliability problems ignored because there is stock available to keep going


l Lean encourages deliberate inventory reduction to uncover problems. Cut the safety inventory:

– If nothing happens, fine. You’ve just made things leaner

– If a stoppage occurs, good. A problem has been recognised, you can find the root cause and fix it.

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l Examples– Inventory exceeding specifies quantity limit– So much inventory at workplace that double

handling is needed– Excessive safety stock

3. Motion

Why a Waste?:

( It interrupts production flow( Increases production time( Can cause injury

Caused by:

( No standard operating procedure

( Poor housekeeping( Badly designed cell( Inadequate training

Distance Travelled: A320 = 1244m A320 = 1044m

Unnecessary Motions

l This splits to 2 sections – the human equivalent to transporting, and ergonomics

– Making people move a long way to get materials, tools or information leads to short cuts, and problems

– If employees have to stretch, bend, pick-up, move to see better, the victim is both the operator (who gets hurt) and the company (who lose quality and productivity)

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Ergonomics

l Awareness of ergonomics is both ethically and economically sound.

l Toyota encourages all employees to be aware of working conditions and to help reduce motion waste

l Video taping is a good tool to get employees to analyse and target improvements in their ergonomic issues

Motion

l Examples– Bending– Reaching– Double Handling at the workplace– More than two turns to be loosen a nut– Walking between spaced work centres

4. WaitingWhy a Waste?:

( Stop/start production( Poor workflow continuity( Causes bottlenecks( Long lead times( Failed delivery dates

Caused by:

( Shortages & unreliable Supply chain

( Lack of multi-skilling/flexibility( Downtime/Breakdown( Ineffective production planning( Quality,design,engineering Issues( ‘Black art’ processes

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l Occurs whenever time is not used effectively –a delay to value adding activities

l Any time that material is not moving or having value added is waiting

l The enemy of smooth flow

l Interrupts the rhythm of work

l May be difficult to eradicate, but the goal remains

Waiting

Waiting

l Employees waiting is also a waste, Can the time be better spent on:

– Another operation– Training– Cleaning– Maintenance– Checking the process or equipment– Practicing changeovers– Improvement projects– Deliberate relaxation

Waiting at bottlenecks

l A “double crime”

l “An hour lost at a bottleneck is an hour lost for the whole plant” – Goldratt, the Goal

l Effective use of bottleneck time is key to regular production, and strongly influences productivity and quality

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Waiting and customers

l Don’t keep customers waiting – eventually they will go away, this is VERY painful

l They may even be prepared to pay a premium for faster service!

Waiting

l Examples– Operators waiting– Operators slower than line– Operators watching machines– Late deliveries

5. Over Production

Why a Waste?:

( Costs money( Consumes resource ahead of plan( Creates inventory( Hides inventory/defect problems( Space utilisation

Caused by:

( MRP push rather than Kanban pull

( Large batch sizes( Looks better to be busy!( Poor people utilisation

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Over Production

l Believed by Ohno to be the most serious waste because it was the root of so many problems

l Making too much, too early, or “just in case”

l Discourages the smooth flow of goods

l Leads directly to excessive lead time, storage time and storage cost

Over Production

l Defects may not be detected early

l Products may deteriorate in storage

l False pressures on work rate generatedAll these increase the risk of defects.

Also overproduction leads to Excessive Work In Queue/Work In Process inventories, separating processes and blocking communication

Over Production

l Overproduction is often the natural state

l People naturally overproduce “just to be safe”

l Output related bonus systems reinforce this

l Prevented by “Kanban” systems

l Motto is “Sell daily? Make daily!”

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Over Production

l Example– “Lumpy” flow– Production above target– Excessive lead-time– Delivery too early

6. Over Processing (excessive)

Why a Waste?:

( It consumes resource( It increases production time( It’s work above and beyond

specification( Can reduce life of component

Caused by:

( Out of date standards( Attitude - ‘Always done it like this’( Not understanding the process( Lack of innovation & improvement( Lack of standard operation

procedures

Over Processing or Inappropriate Processing

l “Using a sledgehammer to crack a nut”

l Thinking in terms of one big machine rather than several smaller ones leads to:

– Less operator “ownership”– Pressure to run the machine as often as possible rather

than just when needed– General purpose machines not ideal for the need at hand– Poor layout (then transportation and communication

issues)

l Ideal is to use the smallest machine capable of producing the required quality positioned at the points of use

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l Inappropriate processing refers to machines or processes that are not quality capable

l It also refers to using people who are not “quality capable” of doing the job required. Here the important question is “Why?” Is it motivation, lack of skill or poor communication of requirements?

Over Processing or Inappropriate Processing

l Example– Variation between operators– Variation from the standard– Having to use a “fast” machine shared between

several lines

Over Processing

7. DefectsWhy a Waste?:

( Adds costs( It interrupts the scheduled ( It consumes resources( It creates paper work( Reduces customer confidence

Caused by:

( Out of control/Incapable processes ( Lack of skill,training & on the job

support( Inaccurate design & engineering ( Machine inaccuracy( Black art processes

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l Included by Ohno to “complete the set”

l Defects cost money

l Toyota view – a defect is an opportunity to improve, rather than as a trade-off (western view)

l Seeing a defect as a waste, has a lot in common with Crosby’s “Zero defect” view

Defects

l Example– Scrap– Rework– Less than perfect yield– Complaints

Defects

Transport

Inventory

Motion

Waiting

Over Production

Over Processing

Defects

What are the seven wastes?

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The New Wastes.

New wastes

l Several people have extended Ohno’s list, here are a few additions:

– Making the wrong product (the right way). Related to the view that Value is in the view of the ultimate customer

– Untapped human potential– Inappropriate Systems and Information. Go for

simple, visual systems. Like Hammer says “Don’t automate, obliterate”

– Energy. Leaving lights or computers on when not needed is a symptom of a wider malaise

New wastes

l The Waste of Untapped Human Potentiall The Waste of Inappropriate Systemsl Wasted Energy and Waterl Wasted Materialsl Service and Office Wastel Waste of Customer Timel Waste of Defecting Customers

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The Waste of Untapped Human Potential

l Ohno was reported to have said “The real objective of the Toyota Production Systems was to create thinking people”

l Many companies learnt the hard & expensive way that automated factory & warehousing does not benefit from continuous improvement

l One example id empowerment to employees, empowered plants are to have 50% more productivity


l “To set human potential free!”

l Requires clear communication between all

l Is sometimes seen as a real threat to operators and middle managers

l Requires cultural trust & respect


l Examples– Not using creative brainpower of employees– Not listening– Thinking that only managers have the ideas

worth pursuing

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The Waste of Inappropriate Systems

l How much record keeping, checking, reconciling is pure waste?

l Example of computers update and develop so quickly a computer of 640K & 30MHz is not suitable to use today!

l It isn’t always the actual construction of the product that consumes all the waste, it is the paperwork or systems

Wasted Energy & Water

l This refers to sources of power– Electricity– Gas– Oil– Coal

l Prices of several sources of energy has risen faster than inflation

l Although all have grown in sophistication there still remains the human element

Wasted Materials

l To reduce the quantities of materials a life cycle approach is required

l This is to conserve material through design and development and during manufacture

l And so beyond the customer when use in recovery or remanufacture

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Service & Office Waste

l All manufacturers are linked with service productionl For instance

– Excess photocopying– Wasted food– Excess meetings– Excessive emails– Over fancy Powerpoint presentations!!

Waste of Customer Time

l When a customer is forced to wait in a queue for value adding services

l More of this waste occurs when the customer has to provide the same information over and over again

l A sub category is the waste of customer time of customer inconvenience, e.g.

– having to wait for a delivery– Or having to a travel for a service not locally offered

Waste of Defecting Customers

l The loss of exsiting customersl A well known saying:

“it costs five minutes more to acquire a customer as it does to retain one!”

l Having won a customer ensure the customer is retained!!

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Seven Service Wastes

l Similar ideas, but from the customer’s viewpoint:

– Delay– Duplication– Unnecessary movement– Unclear communication– Incorrect inventory– Opportunity lost– Errors


How to apply them.

Seven Wastes and Lean

Compress the time required to create value

(Look for one piece flow)

Produce only what and when needed (Kanbans)

Pull

Relentlessly eliminating

waste

PerfectionSpecifyValue

Identify the value stream

Flow

Continuously apply the lean principles

to attack waste

Value defined by the customer.

Agree what this is

Define the chain of value adding steps from raw

material to Customer

1. Transport

2. Inventory

3. Motion

4. Waiting

5. Over Production

6. Over Processing

7. Defects

Reducing the Wastes

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Typical Elements of Throughput Time :-

AddAddValue Value

AddValue

Inspect

ReceiveMaterial

‘Non-Value Added’ Operations Typically Account For95% + of Manufacturing Lead-time

TemporaryStorage

Store

Move Move

Move

MoveMoveWait Wait WaitWait

Identifying Waste in Value Stream Mapping

Examples of Waste Proportion in a Manufacturing Company

Physical Product Environment –Manufacturing or Logistics Flow

Information Environment –Office, Distribution or Retail

Waste Removal Tip!

Alert staff to the seven waste by running a short seminar to explain these wastes. Choose groups of

staff from the main areas of business, e.g. purchasing, production, distribution.

Ask staff to note down their view on specific wastes that occur in their section of the suggestions as to what

could be done to reduce waste.

Then task the staff, either individually or as a group to change one thing each week that will reduce waste

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Service Sector Tip!

If we take the Toyota Production System’s definition of waste, many activities carried out within the service sector provider such as a bank,

insurance firm or retailer add no value.

However, as many of these activities are useful, they might be referred to as service value adding even if strictly speaking they are reducing

the (potential) cost to the customer rather than adding value.

They could, therefore be included within the necessary but non value added category. The reason why they should not be included as value adding activity is that this will direct attention away from their long term

improvement or development


How to eliminate them.

Analysing, Categorising and Eliminating Waste

Observe the types of waste that can be seen during the activity and write the waste seen on a post -it note. At the same time write down a possible solution to the waste (counter measure) on the post -it as shown below.

Operator motionOperator walks 50mto find spanner

Locate and configurespanner at point of use

Waste seen

PossibleCountermeasure

Post-it noteExample

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Analysing, Categorising and Eliminating WasteOnce finished, stick all the post -it notes onto large sheets for each individual waste seen

InventoryOverProduction

OperatorMovement

Transport

IdleTime

BadQuality

Processing


Prioritise into ‘Big hits’ to eliminate NOW and less critical (or harder to eliminate now) hits for elimination in the future i.e concentrate on Low Cost / High Impact wastes initially and then eliminate otherwastes over time to continually rid the activity of waste.

High ImpLow Impact

High ImpHigh impact

Low ImpLow impact

Low ImpHigh impact

Put in place a problem follow up sheet to ensure future actions to remove waste (harder to eliminate wastes) are actively followed up

InventoryOverProduction

OperatorMovement

Transport

IdleTime

BadQuality

Processing


Task No TaskRaised

Description Proposed Solution PersonnelResponsible for

Task

ProjectedSavings

CurrentStatus

Problem Corrective Action Report

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Go and start eliminating the low cost/high impact wastes with quick and cheap fixes and then put actions in place to purchase a more fancy and permanent fix once you are sure the cheap solution works

Wisdom not money !Do it Now, No excuses !Challenge all ideas!

Working Example

Take this flow of activity on a production line

Microsoft Excel Worksheet

Define which activities are; Value Added andNon Value Added


Working Example

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From those activities that are Non Value Added,

Assign the Seven Wastes


Working Example

Analyse & Categorise the Wastes and make suggestions for

Improvements

(Slides 66-68)

Working Example

l Analysing that data there are;– Transport = 11 Operations– Waiting =4 Operations– Inventory = 4 Operations– Motion = 4 Operations– Over Processing = 2 Operations– Defects = 1 Operations

l The main concerns are the Transportationl To resolve this the equipment / processes could be

relocate to create a better flow around the workshop.l A better flow would also solve issues regarding the

waiting times, excess motion times and over produced products stored in inventory.

Working Example

application of the 7 wastes on a production line …ntdung_ise/material/process...ldeming emphasised...

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