H. Detailed Design

The detailed design phase of a typical SIS project entails implementing the "Conceptual Design" through good engineering practices, verifying all the requirements in the SRS (Safety Requirements Specification).

The detailed design is usually performed by the SIS vendor and/or the engineering contractor.

The following considerations are accounted for:

• Verification of site applicable standards
  (API, NFPA, MMS, Authority having Jurisdiction, etc)
• Power and Grounding drawings.
• Field equipment installation drawings.
• Field wiring layouts / junction boxes, etc.
• Intrinsic safety, explosion proof considerations.
• Environmental considerations.
• Logic solver equipment layout drawings.
• Cabinet integration drawings.
• Communications wiring drawings.
• HMI workstations layout.
• Application program development.
• Verification of use of Fixed or Limited Variability Languages.
• Use of V-Model or other verification process.
• Peer review and testing of application software.
• Application software behavior in presence of hardware failures.
• Security implementation (access restrictions).
• HMI screens development.
• Critical alarms implementation.
• Implementation of bypass keys / permissives / inhibits.
• Maintenance procedures development.
• Proof Testing procedures development.
• FAT - Factory Acceptance Test.