Should You Witness a Factory Acceptance Test (FAT)?

This question often arises during the Project’s Precommissioning phase: is it worth allocating company resources to attend Factory Acceptance Tests (FAT) when the EPC Contractor will already be present? If your company has a well-defined Precommissioning, Commissioning (PC&C), and Start-Up philosophy, the decision is often straightforward. However, this isn't always the case in my experience. I’ll share some insights and personal experiences to illustrate the importance of witnessing FATs.

First, what is a FAT?

A FAT is a formal test conducted at the vendor’s or manufacturer’s shop, performed once equipment or systems are fully fabricated and assembled. The goal is to ensure that the equipment meets all functional and operational requirements before shipment. Since Commissioning involves checking equipment installed on-site for compliance with design and specifications, FATs are often considered part of the Precommissioning process.

Key Insights on FATs

In my role, whether as a Project or Process Engineer, I always engage in early discussions with Project and PC&C Managers about several key points:

• We must aim to be as technically independent from contractors as feasible.
• Commission as much as possible at vendor shops or construction yards.
• Participate in all critical FATs and witness as much testing as possible. Ultimately, you get what you inspect.

Offshore developments require extra attention. Main equipment like Emergency Generators, Cranes, and Well Head Control Panels (WHCP) are challenging to modify once offshore. Full performance tests should be conducted before platform deployment whenever possible.

Case 1: Witnessing the Well Head Control Panel (WHCP) FAT

In one of the Hokchi Platforms, the decision was made to have a third party supervise the engineering design and witness the WHCP FAT. Unfortunately, a design flaw was only discovered during offshore Commissioning, which could have been caught during a proper design review or FAT. The result was a much larger problem that required significant effort to fix just before the first well hook-up.

Case 2: Inspecting the 3-Phase Separator at the Vendor’s Shop

For the onshore Early Production Facility, we made the decision to inspect the 3-Phase Separator at the vendor’s shop before shipment. This allowed us to identify minor deviations from the engineering design that were easy to correct at that stage. Had these issues been discovered on-site, they would have significantly delayed first oil and increased costs.