To understand waste.
This one Japanese word must be familiar to everybody.
Muda means waste, particularly any activity which requires work expenditures, but does not constitute the value.
Thus, muda is: malfunctions requiring repairs, production of things which are not needed by anybody, as a result stock and stacks of unsold goods grow; stages of technological process which indeed are not needed; moving of workers and goods from one place to another without a specific purpose; people standing and waiting for succeeding production operation because the previous operation did not give them what they need; goods and service which do not meet customer’s expectation.
Muda is everywhere. It is confirmed even by the most superficial observation of what is going on in every average company.
Luckily, there is a powerful antidote against muda – lean thinking. It enables to specify values, set the activities creating the value in optimal order, perform these activities without disturbances at the time they are needed in the most effective way. Lean thinking gives a possibility of making more and more using less and less – less human effort, fewer devices, less time and less space – and simultaneously it gives us a possibility of approaching the target, that is to supply customers with the exact item they want.
Seven types of waste:
|1||Overproduction||Producing too much and too quickly. Results in improper information or material flow and stock.|
|2||Defects/Mistakes/Shortages||Frequent mistakes of office workers, problems with product quality, deliveries of defected materials.|
|3||Redundant stock||Excessive stock and delays of information or deliveries. Result in excessive costs and improper customer’s service.|
|4||Improper manufacturing methods||Applying improper tools, procedures, methods – often in the situation when simpler ones can be more effective.|
|5||Excessive transport||Redundant movement of people, information or materials.
Results in wasted time, effort and growing costs.
|6||Shut-downs (stops)||Long periods of idleness of people, information or materials. Result in improper flows and long production cycles.|
|7||Redundant movement||Improper organisation of working stands, resulting from non ergonomic arrangement of working space.|
Three types of activities
While considering the problem of waste, it should be started with defining three types of activities performed inside the company (value stream).
- Activities constituting the value: these activities which, from customer’s point of view, cause value increase of product or service.
- Indispensable activities not constituting the value: these activities which, from customer’s point of view, do not cause value increase of product or service, but they are necessary until radical improvement of value stream takes place. It is more difficult to eliminate this type of waste in a short period of time and it should be included in long-term targets.
- Activities not constituting the value: these activities which, from customer’s point of view, do not cause value increase of product or service and they are redundant even under present circumstances of company functioning. These activities are waste. For that reason they should be eliminated immediately or in a short period of time. Example: transfer of the product from the container of one type to another one only to make it easier to move around.
Proportions between these three types of activities in companies which do not implement lean concept:
In actual environment of the product (i.e. production, logistics):
- 5% activities constituting the value,
- 35% indispensable activities not constituting the value,
- 60% activities not constituting the value.
In informational environment of the product (i.e. office, distribution, trade):
- 1% activities constituting the value,
- 50% indispensable activities not constituting the value,
- 49% activities not constituting the value.
Companies striving for lean status concentrate on removing waste both inside and between companies. It has an enormous influence on lean stream. Improved productivity leads to lean operations which are constantly improved in the view of quality and waste elimination.
Systematic attack on waste means the same as systematic attack on the factors causing low quality and basic problems with management over stream flow.
- Jaemes P. Womack, Daniel T. Jones: „Lean Thinking ”, Free Press, New York, 2003
- Mike Rother, Jon Shook: „Lerning to See ”, LEI, Brookline, 2003