What is a “Functional Safety Assessment”?
International Electrotechnical Commission (IEC)61511-1:2016, 3.2.24 – investigation, based on evidence, to judge the functional safety achieved by one or more Safety Instrumented System (SIS) and/or other protection layers.
Functional Safety Assessments (FSA)(s) are judgements made by assessors so as to ensure that functional safety is achieved. The assessments rely more on the awareness and technical competence of the assessor. The Functional Safety (FS) assessment will focus more on the technical aspects in addition to the procedural aspects.
To ‘achieve functional safety’ means that the specified levels of risk reduction are achieved by applying electrical, electronic or programmable electronic safety related systems.
To do that we need to demonstrate that the probability of dangerous failures (or the rate of dangerous failures) is sufficiently low to meet the risk reduction target. That means we need to show that both the probability of random hardware failures and the probability of systematic failures have been controlled.
FSA is a feedback mechanism for senior management. It is a way of monitoring the effectiveness of risk management strategies that rely on automated safety systems (i.e. functional safety).
FSA provides evidence of due diligence in duty of care: Have we made a reasonable effort to reduce the risks that people or the environment are exposed to.
