GEP

Good Engineering Practice

Good Engineering Practice is the body of established engineering methods and standards applied to designing, procuring, installing, and commissioning facilities, equipment, and utilities. It is not a regulation and there is no GEP inspection — but it is the foundation qualification is built on. Work done to poor engineering standards cannot be rescued by a qualification protocol; the protocol simply documents that a badly designed system does what it was badly designed to do.

Its practical role in a regulated project is to carry everything that is not quality-critical, so that qualification effort concentrates where product quality is genuinely at stake. That division — GEP for the majority, formal verification for the critical aspects — is precisely what ASTM E2500 and the ISPE Commissioning and Qualification guidance formalised, and it is what makes risk-based C&Q defensible rather than a shortcut.

Concretely, GEP covers design standards and specifications, materials of construction and their suitability, supplier and vendor assessment, factory and site acceptance testing, calibration and maintenance regimes, documentation and drawing control (P&IDs, as-builts), and handover. Good GEP produces the documentation that risk-based verification then leverages instead of duplicating — which is where its economic value shows up.

• —Established engineering methods applied to facilities, equipment, and utilities — not a regulation.
• —Qualification cannot compensate for poor engineering; it only documents what was built.
• —Carries the non-critical scope so verification effort concentrates on quality-critical aspects.
• —Covers design standards, materials, vendor assessment, FAT/SAT, calibration, maintenance, drawings.
• —Good GEP documentation is what risk-based C&Q leverages rather than duplicates.
• —Formalised in practice by ASTM E2500 and ISPE Baseline Guide Vol. 5.

ASTM E2500-20 and ISPE Baseline Guide Vol. 5 (Commissioning and Qualification, 2nd ed.) define its role in a regulated project; the qualification it supports is required by EU GMP Annex 15 and 21 CFR 211.63 / 211.67 (equipment design, size, location, and maintenance).