Risks associated with process plant operations are analyzed using different techniques, each suited to the task at hand.
Process Hazards Analysis (PHA) describes techniques that examine risk associated with operating chemical processes. Through risk analysis, safeguards may be deemed adequate, or it may be necessary to examine the adequacy of safeguards using a quantitative or semi-quantitative techniques.
It is common practice in many chemical processes to use Safety Instrumented Systems (SIS) to provide the logic control function to engage a safeguard if an undesired deviation of chemical process is detected. Design of the SIS begins with the selection of a performance target for the Safety Instrumented Functions (SIF) employed by an SIS if the undesired deviation occurs. ISA/IEC 61511 refers to the performance target as the Safety Integrity Level (SIL). SIL Selection is an exercise in risk analysis commonly employing Layer of Protection Analysis (LOPA), a semi-quantitative technique in the analysis. In addition to LOPA, we may also utilize the Quantitative Risk Assessment (QRA) technique. A focused QRA (fQRA) is performed in specific areas of concern instead of changing techniques for all the analysis.The assessment of a Safety Instrumented Function (SIF) to determine the appropriate SIL, considers the frequency of initiating events, consequences of inaction, and other independent protection layers to determine the performance target.
Kenexis is a world leader in the development of risk-based techniques for determination of performance targets for safety critical systems. Our consulting staff has substantial background in chemical engineering, process control systems, and instrumentation & control engineering. All of which are critical disciplines for performing a high-quality SIL Selection study. This wide array of knowledge ensures that our engineering consultants bring a knowledgeable and independent view of your situation to facilitate the best possible outcome.