IEC 61508:2010 - Functional Safety of E/E/PE Safety-related Systems 1-8.2: Part 1, 8.2 Functional safety assessment: requirements

One or more people are appointed to judge whether the functional safety the safety systems achieve in their environment is adequate, or the compliance of compliant items (elements, subsystems), with the relevant clauses. Assessors have access to all people involved in the lifecycle and to all relevant information and equipment. Assessment covers every lifecycle phase, including documentation, verification and functional safety management, considers each phase's activities and outputs, and includes all relevant compliance claims by suppliers and others. It may follow each phase or groups of phases, but must be done before the hazards are present. It assesses evidence that functional safety audits were performed, and each assessment considers work since the last one, the plan for further assessments, and the earlier recommendations and how far they were addressed. Each assessment is planned (scope, organisations, assessors, their independence and competence, outputs, integration with other assessments) and the plan approved by the assessors and by those managing functional safety. On completion the assessors record their conclusions, a judgement on adequacy and a recommendation to accept, accept with qualification, or reject. Outputs for a compliant item go to those responsible for lifecycle activities and to the system integrator, and identify the item and version, assumed conditions of use, the evidence relied on, the methods and tools used for systematic capability and hardware safety integrity with justification and data sources, results against the standard and the item's safety manual, and accepted deviations. Assessors meet the competence rules of clause 6.2 (paragraphs 13 to 15) and the minimum independence of Table 4 (by consequence, for lifecycle boxes 1 through 8 and 12 through 16) or Table 5 (by SIL or systematic capability, phases 9 and 10), with any lower independence justified and the X1 or X2 choice reasoned from experience, complexity and novelty.