Functional Safety Management
Compliance with International Functional Safety Standards, such as IEC 61508 and IEC 61511 require that your organization implements a Functional Safety Management System.
The objectives of Functional Safety Management are to identify all technical and managerial activities (work items) related to the safety system over the full lifecycle of the safety system and then make one or more people (departments, organisations) responsible for these activities. Without good Functional Safety Management achieving SIL becomes a lucky shot. You might achieve your SIL target, you might not. With good Functional Safety Management your SIL target is always within reach. Plus you are then completely compliant with the standards.
Functional safety management can be implemented on a per project basis or as part of the normal operating procedures of a company. Either way for each project a safety plan usually documents how FSM is carried out on that project.
Risknowlogy will guide you throughout the process to design, implement and maintain an excellent Functional Safety Management System.
The determination of what Safety Integrity Level (SIL) you need is a key part of the Risk Assessment process. There are several ways to carry this out including Risk Matrix, FTA, LOPA and others. Risknowlogy can help you with the SIL Determination process.
SIL Verification is a much misunderstood term in the minds of many people. It is not just simply a calculation that shows if the PFDavg value of your Safety Instrumented Function is within the band for the respective SIL 1, 2, 3 or 4 but it also includes Verifying whether the architecture can meet the required SIL, whether the Hardware & Software are compliant with the SIL and so on. Risknowlogy can help you completely verify if a SIF meets the SIL Requirement as per the standards, including checking if the PFDavg values are OK.
Risknowlogy has several proprietary tools including the SIL Master Tool and the Markov Master Tool to do this.
Risknowlogy can witness the validation of the SIF to ensure that the Safety Function complies with the Safety Requirement Specifications (SRS) and is also compliant with the relevant standards.
Functional Safety Assessment
Functional Safety Assessment (FSA) is necessary to make sure that professionals who worked on SIL projects actually did what we asked them to do. Did they follow the plan? One or more more professionals do the work, one or more professionals verify the work, and one or more professionals assess that work. Carrying out a Functional Safety Assessment is a key requirement of the standards and Risknowlogy can help you with doing this. Functional Safety Assessment is driven by a lifecycle model and carried out by one or more Functional Safety Assessors.
We have assessment plans for product developers, system integrators, engineering partners and end users.
PFD & PFH Calculations
The average Probability to Fail on Demand (PFDavg) value of the Safety Function is one of the key parameters that are necessary to know if the SIF complies to the desired SIL for Low Demand Systems. Similarly for High Demand Systems, we have the requirement to calculate the PFH (Probability to Fail per hour). Risknowlogy can do these and any related calculations for you using either Markov Models or simplified equations.
Risknowlogy has specialized proprietary software tools (SIL Master and Markov Master) to do these calculations. You either ask us to do these calculations, or use the tools yourself. These tools are chargeable.
FAT / SAT Witnessing
It is always a good idea and also in line with the spirit of the standards to have a completely independent professional carry out the witnessing of the testing of your Safety Instrumented System during a Factory Acceptance Test(FAT) or a Site Acceptance Test (SAT). Risknowlogy has a proprietary system to evaluate if the FAT/SAT was done correctly and can provide an independent report that can be shared with the end user of the system.