Kaizen, lean and the seven wastes

In one paragraph

Kaizen means continuous improvement in small steps, suggested largely by the people who do the job. Lean is the wider system built around removing anything the customer would not pay for.

Kaizen is improvement as an everyday habit rather than a project: many small changes, most of them suggested by the people closest to the work, accumulating over years.

Lean grew out of the Toyota Production System and defines value as whatever the customer would willingly pay for. Everything else is muda — waste — and the seven classic wastes are:

Overproduction (making more or sooner than needed), waiting, transport (moving things unnecessarily), over-processing (more work than the customer values), inventory (stock sitting), motion (people moving unnecessarily), and defects (rework and scrap). An eighth — unused talent — is commonly added.

Just in time follows from removing inventory: parts and stock arrive as needed rather than sitting. It cuts working capital and exposes you to supply shocks, which is a real and sometimes expensive trade.

Why kaizen fails in practice

It requires people to point out problems, which requires them to be safe doing so. In a business where reporting a problem creates blame, the suggestions stop. This is Deming's 'drive out fear' arriving from another direction.

How to actually use it

• Walk the process and count the seven wastes literally, in the room. Waiting and motion are usually the two nobody had noticed.
• Ask the person who does the job daily what wastes their time. Then fix one thing they mention, visibly, this week — that is what determines whether they tell you anything next time.

Where it breaks down

• Lean applied as a cost-cutting programme rather than a waste-removal one produces an under-resourced business with no slack — which was much of the criticism after supply chains failed.
• Incremental by design. It will not produce a new product or a new business model.

If you are being examined on it

Distinguish kaizen (small, continuous, bottom-up) from a one-off restructuring. And give JIT's downside as well as its benefit.

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