Safety Assurance Services Limited

Safety Criteria Calculator

Safety criteria form the foundation on which the Safety Case arguments for tolerability of risk are based and it is therefore essential that these safety criteria are set correctly, are auditable and are traceable back to a recognised source. There are various ways of assessing safety risk and JSP454 promotes the use of a Risk Tolerability Matrix as detailed in DEF STAN 00-56 together with the ALARP principle advocated by the UK Health and Safety Executive (HSE).

Whilst working on a number of safety programmes for MOD projects, Safety Assurance Services have identified that there appears to be a number of ways that safety criteria are set, and that in many instances there is remarkably little commonality or reasoning behind the approaches adopted. In order to try and ensure a common approach, SAS have produced a report that presents a standardised methodology for the setting of safety criteria.  The methodology is consistent with the requirements of DEF STAN 00-56 and JSP454 and is also generic in its nature such that it can be applied to a wide variety of MOD projects and systems.

A prototype software tool called the Safety Criteria Calculator (© Safety Assurance Services, 2002) has been produced using Microsoft Excel that demonstrates the principles of the report.