SIF Response Time Calculations – Are Your SIFs Fast Enough?
About
Safety Instrumented Functions or SIFs are only effective if they act quickly enough to prevent a hazardous event. Calculation of SIF Response Times is a critical performance parameter within SRS that can directly influence the risk reduction achieved from SIFs. The standards IEC 61508 and IEC 61511 require that the SIF Response Times must not exceed the Process Safety Time, that limits the maximum time allowed for a SIF to act.
This webinar aims to define the process for Process Safety Time and SIF Response Time Calculations, breaking the calculations into individual elements with a view to provide a structured, practical methodology that is aligned with IEC 61511. Participants will gain understanding of how to develop PST from worked examples and how to estimate SIF response time, built up from sensor, logic solver, and final element response times. The session bridges theory and practice, offering a practical workflow for calculating, validating, and documenting these parameters.
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Continuing Professional Development
This event can contribute towards your Continuing Professional Development (CPD) hours as part of the IET's CPD monitoring scheme.
30 Jun 2026
12:30pm - 1:30pm
Organiser
- Safety TN
Speakers
Nirav N Chokshi PhD CEng MIET FSEng (TÜV Rheinland)
Senior Design Engineer - Fluor Ltd
Nirav Chokshi holds a BEng, MPhil and PhD degrees in Process Automation and Control. He is currently employed as a Senior Design Engineer with Fluor Ltd. in Farnborough, UK where he specializes in all aspects of design, engineering, testing and validation of control systems within medium-to-large scale process industries. Prior to this, he worked in a principal engineer capacity for the UK nuclear industry where he acted as technical specialist in developing high-integrity process control and safety systems. His particular interests are in the domain of reconfigurable process control, use of AI in process automation and functional safety among others. He is actively engaged in the advancement of global standards and is a member of multiple IEC, ISA and other technical committees. He is also a co-chair of the ISA88 Working Group on Exception Management in Batch Control.
Reasons to attend
CPD
Industry expert speaker