Safety Lifecycle

The safety lifecycle is the structured set of phases defined in IEC 61508 and its sector adaptations that govern the design, implementation, operation, modification, and decommissioning of safety-related systems, used to manage functional safety from concept through end of life.

Last updated: April 2026

Key Facts

Term: Safety Lifecycle
Defined in: IEC 61508 (umbrella); IEC 61511, ISO 26262, IEC 62061 (sector adaptations)
Number of phases: 16 (IEC 61508 reference model)
Coverage: Concept through decommissioning
Owner role: Functional Safety Manager
Required outputs: Phase deliverables verifiable by certification body audit
Typical course duration: 1 to 3 days standalone; integrated into multi-day functional safety programmes
Industries: Process, automotive, machinery, rail, medical devices

What is the Safety Lifecycle?

The safety lifecycle covers every phase of a safety-related system, from initial concept through hazard and risk analysis, allocation of safety functions, design and engineering, installation and commissioning, operation and maintenance, modification, and decommissioning.

IEC 61508 defines the lifecycle in detail, with sector adaptations such as IEC 61511, ISO 26262, and IEC 62061 tailoring the phases to their domains. Each phase has defined inputs, outputs, verification activities, and competency requirements. The lifecycle approach exists because most safety failures originate in early phases (specification, design) and propagate through the system, so disciplined management at each handover prevents avoidable failures.

Safety Lifecycle Phases (IEC 61508 Reference Model)

Phase Group	Activities
Concept and definition	Concept, overall scope definition
Hazard and risk analysis	Hazard identification, risk assessment, tolerable risk targets
Allocation	Safety requirements specification, safety function allocation
Design and development	Realisation of E/E/PE safety-related systems, software and hardware design
Validation	Overall safety validation, integration testing
Installation and commissioning	Installation, commissioning, validation in place
Operation and maintenance	Operation, maintenance, periodic proof testing
Modification	Change management, impact analysis
Decommissioning	Safe shutdown, removal, disposal

According to UK HSE research, more than 60% of control system failures originate in the specification, design, and installation phases combined. The lifecycle structure exists to catch these failures early.

How Functional Safety Training Providers Deliver Lifecycle Training

Lifecycle competency is foundational to almost every functional safety credential, and providers cover it as a recurring theme across IEC 61508, IEC 61511, ISO 26262, and IEC 62061 courses.

Dedicated workshops cover lifecycle management, verification activities, and assessment practice. Delegates include functional safety engineers, project managers, system architects, and assessors. Providers typically deliver lifecycle content through blended formats: self-paced foundation modules combined with instructor-led case-study workshops. The training operation needs structured course catalogues that align modules to lifecycle phases, identity verification at exam, verifiable certificates, audit-ready records that satisfy certification body review, and branded portals for in-house client cohorts on active engineering projects.

Common Questions

What are the main phases of the safety lifecycle?

The phases vary slightly by standard but typically include concept, hazard and risk analysis, allocation of safety requirements, design and engineering, installation and commissioning, operation and maintenance, modification, and decommissioning. Each phase has defined verification and validation activities.

Who is responsible for managing the safety lifecycle?

The Functional Safety Manager or equivalent role, supported by engineers, assessors, and project managers. Roles and responsibilities are typically documented in a functional safety management plan at the start of the project.

How does the safety lifecycle support certification?

Certification bodies such as TUV Rheinland, TUV SUD, and exida assess the lifecycle evidence produced during the project. Audit-ready records of each phase, including hazard analyses, design reviews, verification reports, and validation results, are required for SIL or ASIL certification.

What happens during the modification phase?

Any change to a safety-related system after commissioning triggers an impact analysis to determine whether the change affects the SIL or ASIL, followed by re-verification of the affected lifecycle phases. Without this discipline, original SIL evidence loses its validity.