Division

The manufacturer shall provide the technical service with an explanation of the design provisions built into the safety instrumented system so as to generate safe operation under fault conditions. Possible design provisions for failure in the safety instrumented system are:

1. (a)

   Fall-back to operation using a partial system;

2. (b)

   Change-over to a separate back-up system;

3. (c)

   Removal of the high level function.