Sources of Waste: Overprocessing

by Jan 5, 2021Continuous improvement

Overprocessing is one of the seven sources of waste considered in lean manufacturing or Muda (無駄), the latter a Japanese word meaning “wastefulness; uselessness”.

Overprocessing could be defined as adding more value to a product than what the client or customer actually requires (e.g., beautifying areas that will never be seen).

Overprocessing, easily defined as unnecessary work, will inevitably generate several direct and indirect costs, associated in particular with the equipment and materials used, the workers’ paid time, not to mention value that is lost because it is not paid for by the client.

Lack of efficiency is another symptom of overprocessing as workers could spend the wasted time doing other value-adding tasks that are salable or requested by the client.

Overprocessing usually occurs when working methods are not clear or standardized enough. When workers are highly skilled, they find themselves performing tasks that do not add value to keep their level of efficiency high.

The non-standardization of work methods which could lead to overprocessing can cause great variability in the quality of products since work methods depend on people and can change from one workstation to another. Something that should generally be avoided in terms of statistical process control.

The waste caused by overprocessing can be effectively eliminated or reduced by standardizing working methods which, with adequate training as well as the establishment and clarification of quality standards, can have an impact on other types of waste.

Finally, standardized working methods must not become a “Trojan Horse” to introduce overprocessing, because, if the latter stems from a design problem, compliance with standards will not allow this “hidden” overprocessing to be dealt with. It is therefore necessary that the design of the product or process be limited to the client’s expectations without exceeding them (evaluating designs to ensure the need for excessively tight tolerances for example) to reduce any form of overprocessing.

These standard operating procedures (SOPs), combined with quality standards, can also help clarify specifications and acceptance standards.

Review designs with techniques such as value engineering and analysis to identify opportunities to remove excessively tight tolerances.

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Intervention Prévention concentrates its operations in the field of work safety, offering specialized services following Standards CSA Z462 – Workplace Electrical Safety, CSA Z460 – Control of Hazardous Energy: Lock-out and Other Methods, and CSA Z432 – Safeguarding of Machinery.


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