Learn Automation with MINATA #08: Energy Isolation: Seven Lockout and Tagout Steps Before Machine Repair
MINATA turns the Vietnamese source into an evidence-led guide. lockout and tagout must protect people, equipment, data, and repeatable operation when the boundary changes.
Start with the real condition
Write the input condition, expected result, acceptance limit, failure symptom, and measurement method before touching a meter, lock, program, or setting. Assign an owner to every step and change.
Core checks
- All electrical, pneumatic, hydraulic, gravity, thermal, and stored energy: record condition, owner, method, and pass/fail evidence.
- Isolation points and personal locks: record condition, owner, method, and pass/fail evidence.
- Dissipation, blocking, and zero-energy verification: record condition, owner, method, and pass/fail evidence.
- Authorized worker, affected worker, and communication: record condition, owner, method, and pass/fail evidence.
- Repair boundary and shift handover: record condition, owner, method, and pass/fail evidence.
- Removal, inspection, and controlled restart: record condition, owner, method, and pass/fail evidence.
| Failure mode | Symptom | Verification |
|---|
| Boundary not identified | Wrong reading, unexpected motion, or restart | Test the real source and fault case |
| Procedure step omitted | Evidence missing or unsafe state | Walk the procedure with a second person |
| Documents out of sync | Correct label, wrong revision | Baseline program, drawing, and work instruction |
1. Review pass: function and boundary
Review function and boundary for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
2. Review pass: energy or signal path
Review energy or signal path for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
3. Review pass: process and operator
Review process and operator for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
4. Review pass: measurement and evidence
Review measurement and evidence for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
5. Review pass: failure and recovery
Review failure and recovery for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
6. Review pass: maintenance and handover
Review maintenance and handover for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
7. Review pass: revision and access
Review revision and access for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
8. Review pass: supplier and training
Review supplier and training for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
9. Review pass: safety and misuse
Review safety and misuse for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
10. Review pass: data and audit
Review data and audit for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
11. Review pass: commissioning
Review commissioning for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
12. Review pass: field feedback
Review field feedback for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
13. Review pass: acceptance
Review acceptance for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
14. Review pass: final release
Review final release for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
15. Review pass: function and boundary
Review function and boundary for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
16. Review pass: energy or signal path
Review energy or signal path for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
17. Review pass: process and operator
Review process and operator for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
18. Review pass: measurement and evidence
Review measurement and evidence for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
19. Review pass: failure and recovery
Review failure and recovery for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
20. Review pass: maintenance and handover
Review maintenance and handover for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
21. Review pass: revision and access
Review revision and access for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
22. Review pass: supplier and training
Review supplier and training for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
23. Review pass: safety and misuse
Review safety and misuse for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
24. Review pass: data and audit
Review data and audit for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
25. Review pass: commissioning
Review commissioning for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
26. Review pass: field feedback
Review field feedback for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
27. Review pass: acceptance
Review acceptance for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
28. Review pass: final release
Review final release for lockout and tagout. The key risk is energy source identification, isolation, dissipation, verification, and controlled restart. Define lower and upper boundaries, the simultaneous worst case, evidence source, owner, and change trigger. Confirm drawing, circuit, program, label, procedure, inspection, and training use the same revision. Test normal operation, stop, restart, wrong input, interruption, and a controlled fault. Record actual condition, value, unit, instrument or log, person, time, pass/fail, and next action.
MINATA release checklist
- [ ] Function, boundary, and failure symptom are written.
- [ ] Energy, signal, procedure, and ownership are clear.
- [ ] Six topic checks have evidence and pass/fail limits.
- [ ] Operation, isolation, measurement, test, and recovery were tried.
- [ ] Revision, access, training, and audit records agree.
Good automation engineering makes a safe state observable and repeatable. For lockout and tagout, evidence that people and machines remain protected is the MINATA standard.
Public references
- MINATA Q-up design practice and internal review checklist.
- Applicable electrical, safety, control, or maintenance standard selected by the project owner.
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