Functional Safety 2014

ii) Safety function seriously flawed:

will only partly work or work too late

Challenges in managing changes post logic-solver FAT – examples:

•

Part of logic missing (some C&E intersections not programmed) – particularly a risk for

complex logic with multiple inputs or outputs, some of which may be “convenience

actions”

•

Trip settings incorrect.

•

Timer periods incorrect.

•

Incorrect instrument range – usually introduced due to changes.

Neil Wakeling, August 2014