The 7 Wastes (Seven forms of Muda)

The 7 wastes explained

Waste is the use of any material or resource beyond what the customer requires and is willing to pay for.

Lean Manufacturing aims to identify and eliminate waste to improve the performance of the business.

Shigeo Shingo identified Seven forms of waste (Plus one The eighth waste, under utilization of people) These 7 forms of waste are shown below

1. Over Production 6 sigma training

To produce sooner, faster or in greater quantities than the absolute customer demand

Manufacturing too much, too early or Just in Case

Overproduction discourages a smooth flow of goods or services

Takes the focus away from what the customer really wants

Leads to excessive inventory

Caused by:

MRP push rather than kanban pull

Large batch sizes

Looks better to be busy!

Poor people utilisation

Lack of customer focus

Why a Waste?:

Costs money

Consumes resource ahead of plan

Creates inventory

Hides inventory/defect problems

Space utilisation

2. Inventory

Any raw material, work in progress (WIP) or finished goods which are not having value added to them

Caused by:

Production schedule not level

Inaccurate forecasting

Excessive downtime/set up

Push instead of pull

Large batching

Unreliable suppliers

Why a Waste?:

Adds cost

Extra storage space required

Extra resource to manage

Hides shortages & defects

Can become damaged

Shelf life expires

3. Motion

Adds cost

Motion is the movement of man

Waste motion occurs when individuals move more than is necessary for the process to be completed

Caused by:

No standard operating procedure

Poor housekeeping

Badly designed cell

Inadequate training

Why a Waste?:

It interrupts production flow

Increases production time

Can cause injury

4. Waiting

People or parts that wait for a work cycle to be completed

Where are the bottlenecks?

What are the major causes of lost machine availability?

What are we doing to improve machine availability?

Do people wait on machinery?

Caused by:

Shortages & unreliable supply chain

Lack of multi-skilling/flexibility

Downtime/Breakdown

Ineffective production planning

Quality,design,engineering Issues

Black art processes

Why a Waste?:

Stop/start production

Poor workflow continuity

Causes bottlenecks

Long lead times

Failed delivery dates

5. Transportation

Unnecessary movement of parts between processes

Complex material flow paths

Poor close coupling

Wasted floor space

Unnecessary material handling

Potential damage to products

Caused by:

Badly designed process/cell

Poor value stream flow

Complex material flows

Sharing of equipment

Why a Waste?:

Increases production time

It consumes resource & floorspace

Poor communication

Increases work in progress

Potential damage to products

6. Over-Processing

Processing beyond the standard required by the customer

By improving processing efficiency we ultimately use less resource to achieve the same customer satisfaction

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

Why a Waste?:

It consumes resource

It increases production time

Its work above and beyond specification

Can reduce life of component

7. Non-Right First Time (Scrap, Rework and Defects)

A defect is a component which the customer would deem unacceptable to pass the quality standard

Defects reduce or discourage customer satisfaction

Defects have to be rectified

Rectification costs money with regard to time effort and materials

Defects in the field will lose customers

Right first time is the key

Caused by:

Out of control/Incapable processes

Lack of skill,training & on the job support

Inaccurate design & engineering

Machine inaccuracy

Black art processes

Why a Waste?:

Adds costs

It interrupts the scheduled It consumes resources

It creates paper work

Reduces customer confidence

The 8th Waste

Under utilisation of people. People are your greatest asset, learn to get the best out of them.