Jidoka and andon: detect, respond, verify restart

Jidoka and andon: detect, respond, verify restart

Detection only protects customers when it triggers a response. Define the normal condition, the abnormality signal, who responds and what must be verified before work resumes. When a problem appears, follow the approved stop and containment rule so suspect work does not escape. The responding leader or specialist resolves the condition and confirms the restart criteria. Record recurrence for deeper investigation. Different processes have different stopping conventions; a fixed-position production stop is not an emergency-stop instruction. A red lamp without response ownership and follow-through merely displays the problem. The system must help people surface trouble early.

Follow the method

1. Detect abnormality
2. Signal and protect
3. Qualified response
4. Restart criteria met?
5. Resume and learn

A reset is not the restart decision

Fictional assembly cell: operator Leon sees an incomplete fastening confirmation on unit V18 and raises the approved help signal. A colleague clears the display and proposes restarting because the light is no longer on. The response card requires confirmation of the fastening result and controlled review of potentially affected units.

Follow the method

1. Detect
2. Contain
3. Respond
4. Verify
5. Learn

The light is off, but the condition remains

Connect an abnormality signal to containment, response ownership and verified restart, distinguishing signal reset from evidence that the process is ready.

Fictional assembly cell: operator Leon sees an incomplete fastening confirmation on unit V18 and raises the approved help signal. A colleague clears the display and proposes restarting because the light is no longer on. The response card requires confirmation of the fastening result and controlled review of potentially affected units.

Role: Operator, team leader and authorized quality/equipment responder.

Normal condition

An abnormality receives a timely response; unsuitable output does not proceed, and restart follows the approved acceptance conditions.

The gap

Clearing a display has been confused with correcting and verifying the underlying condition.

• Use the site’s actual approved stop/help procedure. A process andon is not a substitute for emergency response.
• This exercise gives no equipment setting, isolation sequence or authority to override safeguards.

1. Treat the condition as the trigger

   Leon identifies the observed incomplete confirmation and uses the approved response route. He records the unit identity and time, without guessing that the sensor or operator caused it.

   Why: An andon makes an abnormality visible and requests response. A color change is not a root-cause finding.

   Evidence: V18 and the missing confirmation are recorded as facts.

2. Preserve the affected-output boundary

   The responder uses the last verified evidence at V15 to identify V16–V18 for controlled review under the local procedure. Their status remains distinct from accepted output.

   Why: Containment needs a justified boundary. Looking only at the signaled unit may miss earlier affected work; assuming every unit is defective also exceeds the evidence.

   Evidence: Three potentially affected units identified; defect status not yet determined.

3. Respond through the authorized owner

   The team leader brings the designated responder to the actual condition, supplies the record and maintains the approved stopped/held state as required.

   Why: The operator needs support and a known response, not pressure to clear the board. Technical adjustments belong to authorized people and procedures.

   Evidence: Named responder, response time and investigation record are visible.

4. Verify before restart

   Check the prescribed process conditions and acceptance evidence, then record the authorized restart decision and the disposition of affected output. If criteria are unmet, continue the response.

   Why: Reset, repair, verification and product disposition are separate events. None should be inferred from the display alone.

   Evidence: Restart requires documented criteria met; V16–V18 remain controlled until disposition.

5. Close the learning loop

   Return the result to Leon and review recurrence, response delay and any weakness in detection or standard work. Update and teach approved changes through their owners.

   Why: Without feedback, people may stop raising useful signals. The system should learn from the abnormality rather than reward silence.

   Evidence: Operator feedback and a recurrence review are part of the completed response.

The responder cannot attend immediately

The designated responder is unavailable and a production target is approaching.

Follow the approved escalation and safe-state procedure; the target does not create restart authority.

A missing response route is a system issue to expose, not a reason to substitute unverified output.

Escalation owner, current state and next contact are recorded.

Run a practice session

Materials

• Unit identity cards and response-state tokens
• Approved-procedure placeholder rather than invented technical instructions

1. Read the abnormality · 4 minutes

   What was observed, and what is only a guess?

2. Set the review boundary · 8 minutes

   Why start with V16 rather than only V18?

3. Work the labeling variant · 8 minutes

   What does resetting the light establish?

4. Close the response · 5 minutes

   What should the operator hear back?

Debrief

• Challenge pressure to treat the target as restart authority.
• Distinguish a normal process help signal from emergency procedures.

Write separate detect, contain, respond, verify and learn records; do not merge them into a single “fixed” box.

Transfer into the work

Owner: Cell leader with authorized quality/equipment owners

Record: Abnormality, containment, verification, disposition and feedback record

Review: At response closure and the next recurrence review

Evidence: Criteria-based restart, controlled affected output and timely operator support

Escalate response capacity and unresolved conditions; retain the required controlled state.