Definition
English tends to collapse two different actions into one word — “fix.” Japanese problem-solving practice keeps them apart:
- Taisho (対処) — handling / containment. The immediate response that contains the symptom so work can continue and the customer is protected. Replacing the blown fuse, sorting and reworking suspect parts, adding a temporary inspection. It addresses the effect, buying time, but it does not touch the cause.
- Taisaku (対策) — countermeasure. The action aimed at the verified root cause so the problem does not come back. It addresses why the problem happened, not just that it happened.
Both are legitimate, and a fast taisho is often necessary to protect the next process while you investigate. The discipline is to know which one you are taking — and not to mistake the first for the second.
Japanese Origin
- 対 (tai) — facing, dealing with, responding to
- 処 (sho) — to handle, manage, dispose of → 対処, handling a situation
- 策 (saku) — a plan, scheme, measure → 対策, a countermeasure
“Dealing with it” versus “a measure against it” — the first manages the symptom in front of you, the second is a deliberate plan against the cause.
The Common Failure
The most common way a “solved” problem returns is declaring victory at the taisho and never completing the taisaku. Containment actions — segregating suspect parts, adding inspection, reworking — feel like resolution because the symptom disappears, but the cause is untouched and the problem recurs.
A countermeasure can be ranked by how fundamentally it removes the cause: weak ones lean on human vigilance, stronger ones detect the abnormality in process (poka-yoke), and the strongest change the conditions so the problem cannot occur at all (mizen-boushi). The strongest taisaku is prevention. See the eight steps of Toyota problem solving for where this sits in the method.
Common Misunderstandings
Calling containment a countermeasure. Sorting, rework, and added inspection are taisho — they protect the customer while you learn, but they are not taisaku and should never close a problem.
Stopping when the symptom disappears. A symptom gone is not a cause removed. Until the taisaku is in place and confirmed, the problem is only hidden.
Skipping taisho to look rigorous. The opposite error: leaving the customer exposed while chasing root cause. Contain first, then counter — just don’t confuse the two.