Our Design Review Services Overview
Design Reviews Built Around Your Priorities
SIL Safe focuses your design review process on three core areas of the safety lifecycle, helping you build a clear path from risk identification to documentation and verification.
PFDavg and STR Calculations
We help deliver SIL verification by calculating PFDavg, RRF, and STR using accurate, traceable methods grounded in IEC 61511.
Coordinating the SRS
We help define each Safety Instrumented Function by developing a complete SRS that reflects your risk studies, logic expectations, and lifecycle needs.
General Facilitation:
We lead workshops, coordinate vendors, and review documentation to keep teams aligned from concept through commissioning.
How We Guide Functional Safety Design
We support design efforts by focusing on the real-world challenges that process industry teams face under IEC 61511-1. Whether you’re planning a new SIS or refining an existing one, our structured facilitation helps teams progress from risk assessment to detailed design with clarity and momentum.
Our reviews address both the technical and organizational dimensions of the design phase. That includes aligning calculations like PFDavg and STR with the risk profile, confirming Safety Requirements Specifications (SRS) reflect what was agreed in the HAZOP or LOPA, and ensuring documentation is consistent, usable, and traceable.
We believe design reviews should offer more than checklists. Our team helps surface blind spots, resolve ambiguities, and clarify logic so that everyone—from operations to vendors—is on the same page. The goal is a compliant, resilient SIS design that supports your safety goals without slowing the project down.
Each facility has its own pace and constraints. That’s why our approach is flexible—we adapt our review structure and cadence to match your needs, whether that’s early-stage workshops or late-stage verification of third-party packages.
Design with Confidence
Ready to Move from Risk Study to Real Design?
Fresh out of a HAZOP or refining a LOPA, SIL Safe helps teams move forward with support informed by IEC 61511 and tailored to your timeline.
- Practical guidance on what needs to be calculated.
- Support across documentation, facilitation, and technical details
- Designed to meet the pace and reality of your team
A Practical Approach to SIS Design
Support for Design Reviews
We bring structure, clarity, and technical accuracy to the design phase of Safety Instrumented Systems. Our process is grounded in IEC 61511-1 and tailored to support your team through the practical challenges of real-world projects.
Prepare PFDavg and Spurious Trip Rate (STR) Calculations
We support your team by helping to collect and validate the failure rate data necessary to model SIL performance. This includes performing Probability of Failure on Demand (PFDavg) calculations and determining Risk Reduction Factor (RRF) targets that align with the desired SIL.
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We also calculate expected Spurious Trip Rate (STR) to support system reliability goals. Our methods follow IEC 61511 guidance and use trusted tools.
Coordinate the Safety Requirements Specification (SRS)
Team facilitation
We work closely with engineering and operations teams to develop a clear, standards-aligned Safety Requirements Specification (SRS). The SRS ties directly to the HAZOP, LOPA, and hazard assessment findings, forming the technical foundation for each Safety Instrumented Function.
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We ensure the specification defines the function, integrity level, and operating expectations in a way that’s traceable, auditable, and usable throughout the lifecycle.General Design Process Facilitation
Design Leadership That Keeps Teams Aligned
Our facilitation services help guide teams through the SIS design phase with structure and clarity. We lead workshops, coordinate between disciplines, and catch compliance gaps early.
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We help maintain momentum by resolving misalignment, documenting decisions, and surfacing open questions. Our goal is to reduce confusion, keep documentation usable, and support traceability from concept to commissioning.
Common Design Review Questions
Not sure what kind of design support your project needs? These frequently asked questions cover the basics — from timing and tools to third-party verification.
How early should we bring in a design reviewer?
The earlier, the better. We can help clarify roles, streamline assumptions, and avoid costly rework down the line.
Do you work with client-selected tools or software?
Yes. We adapt to your tools whenever possible, whether it’s exSILentia, Vertigo, or spreadsheets—and ensure calculations remain traceable.
Can you help us finalize or verify a third-party’s work?
Absolutely. We often provide independent reviews of vendor- or contractor-developed SIL packages.
Is your support limited to greenfield projects?
Not at all. We work with both new and existing facilities, including brownfield upgrades and retrofit SIFs.