Problem Statement

1. Problem Statement • Safety is of increasing importance in industrial environments. SIL (Safety Integrity Level) • assessments are the standard way to guarantee the safety and risk reduction of the functional • safety circuit. The EN-IEC 61508 defines the requirements for the functional safety circuits and the procedure for performing a SIL assessment. Currently, the contribution of random errors to the SIL is being validated in most cases by means of reliability calculations of the circuit. This calculation approach has several shortcomings: • Reliability data of components (and environmental conditions under which the data was • obtained) is not always available and obtaining this data from supplier can be time • consuming. • The result of the calculation approach is critical dependent on the reliability data and • diagnostic coverage of components and hence might be inaccurate. • The calculations do not account for bad batches of components, which can have a major • impact on safety. • Therefore it seems an interesting approach to include experimental validation in the SIL assessment for random failures. Project Goals: The main goal is to establish an efficient integrated method for the experimental validation of safety levels for random failures that is accepted for certification or qualification Economic Value: • The integrated SIL verification methodology should have following advantages over • the current practice: • The method should be faster. • The method avoids failures of safety function because of bad component batches. • The method will create a more accurate estimation of the reliability of the safety function. FMTC vzw ■ Celestijnenlaan 300 D bus 4027 ■ B-3001 Leuven (Belgium) ■ Tel +32 16 328050 ■ Fax: +32 16 328064 ■ info@fmtc.be ■ www.fmtc.be