An introduction to functional safety assurance
If you’ve ever wondered what’s meant by the term functional safety assurance, you’re not alone. Simply put, functional safety assurance is the process by which we ensure that safety-related systems do what we need them to do, when we need them to do it, so that risk is maintained at tolerable levels. But what does this mean in practice?
Cyber-security meets functional safety
The cyber-threat to industrial control systems is very real, as demonstrated by high profile attacks in recent years.
Introduction to PSA
Probabilistic Safety Assessment (PSA) provides an integrated and structured safety analysis for a nuclear facility that combines consideration of engineering design and operational features in a consistent framework. This established and systematic technique identifies all significant fault sequences which can lead to a radiological release and assesses their contribution to risk, on a best-estimate basis.
Introduction to QRA
Risk is defined as the combination of the probability of an event and the consequences of the event, but how do you go about undertaking a full Quantitative Risk Assessment (QRA) for an offshore oil and gas facility or an onshore petrochemical plant?
An introduction to safety-critical software
Software is often used to implement the functionality of safety systems because it can be designed to handle complex functionality, is accurate and repeatable, and can be cheaper than hardware solutions. However, there are many examples of safety systems which have failed due to software related faults.
Functional safety: a proportional approach to legacy safety systems
The requirement for identification, specification and maintenance of Safety Instrumented Systems (SIS) is contained throughout legislation, with the industry-wide good practice standard being IEC 61508, Functional safety of electrical/ electronic/ programmable electronic safety related systems. SIS are specific electrical or electronic systems that prevent or mitigate the effect of a hazard.
Closing the safety gap – safety integrity level selection using LOPA
Safety instrumented systems are often used to reduce the risk associated with a potentially hazardous process or plant. It is usual to express the level of risk reduction required as a safety integrity level or 'SIL'. As such, selecting an appropriate SIL is a fundamental step in any safety specification and there are a number of different methods employed, depending on industry.
Cyber risk for the rail engineer
Cyber security issues have pervaded almost all aspects of life as daily data breaches and hacked websites testify. In the rail sector, where previously isolated control systems have become connected to the internet, we have seen a new challenge emerge for engineers tasked with ensuring system reliability, availability, maintainability, safety and now security (RAMSS).