The Operational Ex Lifecycle: An Eight-Step Decision Loop

A single diagram for the whole Operational Ex series: eight steps that run from knowing the EPD, HAC and X conditions, through verified installation, operation, findings and the decision point, to corrective action, re-verification and authorized return to service. Then back to operate. The loop is deliberately closed, because an Ex-safe condition is demonstrated repeatedly rather than once. At the centre sits the Head of Operations with three essentials: competence, tools and the authority to STOP.

A circular eight-step Ex-safety cycle for a Head of Operations, from Know and Verify through Operate, Find, Decide, Act and Verify Again to Return to Service, around a central worker figure.

Head of Operations asked me to draw the lifecycle of Operational Ex

1. KNOW
EPD / HAC → Ex Register → Certificates → X-conditions → Site requirements
↓
2. VERIFY
Installation → Initial inspection → Ex-safe condition demonstrated
↓
3. OPERATE
Use equipment within defined conditions → Monitor the plant
↓
4. FIND
Inspection / maintenance / operator observation → Defect, change or deviation?
↓
5. DECIDE
Safe to continue?
→ YES → Define action + priority → Continue under controlled conditions
→ NO / UNCERTAIN → STOP / isolate / escalate
↓
6. ACT
Maintain → Repair → Replace → Correct → MoC where required
↓
7. VERIFY AGAIN
Was Ex integrity restored? → Inspection / documentation / engineering verification
↓
8. RETURN TO SERVICE
Authorize → Update Ex Register / EPD / records

↺ Back to OPERATE

The key is an operational decision loop:
Know → Verify → Operate → Find → Decide → Act → Verify → Authorize → Repeat.

And at the centre sits the Head of Operations / Operator, with three essentials: Competence + Tools + Authority to STOP.

The Operational Ex Lifecycle: An Eight-Step Decision Loop

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