Table 1 Ohno’s seven sources of waste in organisations

Overproduction (OPN)

Parts are manufactured without any new order or demand from customer. OPN leads to excessive work in process stocks.

Large batch size, unstable schedule, unbalanced cells, inaccurate information on demand.

Excess inventory

Storage of products with no order on hand.

Excess inventory, large batch size, long change over time.

Waiting

Idle time for machines or workers due to bottlenecks of ill-planned production flow.

Long changeover, unreliable process, time required to perform re-work.

Motion

Unnecessary motions of workers, which divert them from actual processing work. Motion involves poor ergonomics of production.

Poor layout, poor method design, large batch size, poor workplace organisation.

Transportation

Movement of materials that do not add any value to the product.

Poor layout, large batch size, multiple storage locations.

Over-processing

Unintentional conduct of more processing work than warranted by customer requirement.

No standardisation of ideal techniques, unclear specification, or quality acceptance standards.

Defects

Production with incorrect specifications, physical defects leading to increase in cost.

Inadequate training, skill shortage, operator error, excessive stock.