Design / Operations Performance Standard

A Performance Standard (PS) describes the performance criteria for a Safety Critical Element (SCE) and used as the basis for design, technical and operational integrity verification. Performance standards are expressed in terms of functionality, availability, reliability, survivability, and dependencies/ interactions with other SCEs. SCEs and Performance Standards follow a one-to-one relationship where each SCE has its own Performance Standard.
Functionality
Functionality is an expression used to define what the system or equipment is required to achieve to ensure design integrity.
Reliability and Availability
Reliability is defined as the required probability that the system or equipment will operate on demand, when required.
Availability is defined as the extent to which the system or equipment is required to retain its functional integrity.
Survivability
Survivability defines the external loading events such as fires, explosions, or extreme weather, associated with the various MAHs against which the system or equipment is required to retain its functional integrity.
Dependencies and Interactions
This is used to identify other systems or equipment which are critical to the functionality of the primary system or equipment. By identifying these dependencies and interactions it is ensured that all interfaces have been covered.

There are two types of Performance standards.
Design Performance Standards.
Design Performance Standards (Whenever required) must be developed during the Define phase. They shall provide a list of key functional criteria to which the SCE must comply with during the design. Design performance standards should also identify and list assurance and verification activities for design, procurement, fabrication, construction &commissioning phase. In practice the content of the performance standards will be largely taken from the design and engineering standards that apply to the item or SCE. However, information may be also taken from the basis for design, the design philosophies, HEMP Studies such as HAZID/HAZOP, Design Review, Layout Reviews, Fire & Explosion Analysis, QRA, IPF, SAFOP, etc.
The Design Performance Standards will mature further during the execute phase and will check that the SCEs have been procured, fabricated, and constructed as designed. The existing QA/QC procedures and practices should be used to support the Design Performance Standards. The design must consider operational demands so that suitability can be ensured into the operate phase.
Operations Performance Standards.
Operation Performance Standard is a statement, which can be expressed in qualitative or quantitative terms of the functional performance required of a SCE and which is used as the basis for managing the risk from the Major Accident Hazards (MAH). Defining and ensuring compliance with suitable Performance Standards provides assurance that the SCE is and will remain a barrier to the identified MAH.
Operation phase performance standards helps organisation to align maintenance and inspection strategies, execute assurance activities and to manage deviations. An operation phase global performance standards templates should be available with Maintenance &Integrity (M&I) team. When required, project team should contact M&I team for latest revision of operation phase global performance standard template.