A — EPC PROJECT PHASE

Engineering · Procurement · Construction · What happens here: Hazardous area classification is defined. Ex equipment is selected and installed. Certificates, drawings, and documentation are produced

Notes: Compliance exists only at this moment in time. The protection concept is static, the installation is not, there are numerous revisions. 

B — END USER / OPERATOR PHASE

Operation · Maintenance · Modification · What happens: The site operates based on original design. Repairs, replacements, and upgrades start immediately. Small changes accumulate over time

Notes: Context is lost. Decisions are made without full design intent. Engineering slowly turns into assumption

C — END USER BECOMES EPC (UNINTENTIONALLY)

Without authority · Without competence · Without mandate · What happens: Equipment is modified or replaced. Zones, EPLs, interfaces are reinterpreted. Ex-related decisions are taken locally (focusing on functionality).

Notes: The operator is now performing EPC decisions, but without EPC responsibility · EPC competence · EPC documentation discipline

D — EPC AGAIN (UNPLANNED & UNCONTROLLED)

Silent re-engineering of the site · What happens: The installation redesigns itself over time. Documentation diverges from reality. The original Ex protection concept collapses.

Notes: Compliance is assumed, not demonstrated. Certificates no longer reflect the real installation (compliance to design stage not there).

The site has become a project again — without a project.

Notes: After D, the system quietly returns to A: Re-assessment · Re-engineering · Re-documentation. But only after incidents, audits, or failures.

Lifecycle ownership of Ex compliance: ✔ Traceable decisions ✔ Change history ✔ Zone–equipment consistency ✔ Responsibility mapping ✔ Evidence over time

Lifetime tracking of Ex compliance: Ex compliance is not a handover milestone. It is a continuously engineered state (compliance to design stage).

Keep up the good work!

Arpad
veress@exprofessional.com