Managing safety system performance is one of the most important tasks for the maintenance function. The cost associated with testing and maintaining safety systems is high. Finding the optimal time for testing calls for a balance between the benefit of improved reliability and the cost of testing.
Our approach
DNV’s approach to safety system reliability covers both the design and the operational phases and recognises the safety function as an integral part of both SHE-activities and maintenance activities.
The following are the main activities during a project/design phase:
- Hazard identification and the need for risk reduction
- Risk assessment – a dedicated risk assessment to set reliability requirements to the safety functions – SIL (Safety Integrity Level)
- LOPA-analysis (Layer of Protection) – taking into account all risk reduction measures available
- Reliability analysis – to analyse the actual reliability
- Development of the Safety Requirements Specification (SRS) used as part of the vendor contract and documentation
- Integration and design of the safety system, define requirement to the architectural constraints, assurance of adequate hardware reliability and avoidance/control of systematic failures
During the operational phase, we:
- Analyse the failure history and update the testing regime
- Advise on KPI-setting and aggregation
- Advise on how operational unintended testing can be used as part of the reliability estimation
The international standards IEC 61508 and IEC 61511 are widely accepted as the basis for specification, design, implementation and operation of safety-related electronic systems. The requirements of IEC 61508 apply for companies delivering components as well as total systems. We have experience of interpreting and applying this standard cost effectively.
Benefits
- High safety performance – following the company and statuary legislative requirements
- Cost saving by running an optimised process
- Learn from DNV’s experience with IEC 61508 and IEC 61511
- Ensure that everything is done, right and on first trial
- Increase the organisation’s safety performance
