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• How to define requirements for safety systems and barriers, with basis in risk analyses
  
  Safety integrity level (SIL) is a key reliability performance measure used for safety-critical systems. The SIL requirements are identified in an extension of the risk analysis, using methods often refered to as SIL allocation, SIL targeting and SIL classification. Key methods like Layers of protection analysis (LOPA), risk graph, and minimum SIL are presented and discussed.
  
  Some examples showing the relevance of this topic may be found with consultancy companies, such as with Safetec, Lloyd's Register Consulting, and DNV-GL (link to the GL-part of the services), and Lilleaker Consulting.
• Methods used to determine the reliability of safety instrumented systems –  systems.
  
  In TPK 4120, some analytical formulas were introduced to calculate the average probability of failure on demand (PFD). It was also shown how the average PFD may be calculated using Markov methods and fault tree analysis. This reliability measure is of high importance in relation to SIL, as a relationship is established between a SIL requirement and the maximum PFD tolerated for a safety function. In this course, we go one step further and introduce some other methods for quantifying the PFD: The analytical formulas presented in a standard called IEC 61508 (in part 6), which builds on slightly different assumptions than the analytical formulas from TPK 4120. In addition, we will introduce the PDS method and Petri Nets

How to define requirements for safety systems and barriers, and how to assess the reliability of safety instrumented systems with background in IEC 61508 and related standards. This includes SIL allocation, risk acceptance criteria, requirements for design of technical and operational barriers, alternative strategies for treatment of common cause failures, various methods for determining proof test intervals, and trade off between safety and regularity. Within maintenance optimization the following topics are covered: Age, block, and minimal repair policies. Optimisation of intervals and intervention level in condition monitoring models. Optimum grouping of maintenance activities. Spare part optimisation. Reliability Centred maintenance. Data collection and analysis. In relation to technical safety we study how the result from the risk analysis may be utilized to assess the effect of various safety system configurations, and combination of these under various constraints.

Tutorials

Reliability analyses:

Tutorials will focus on the application of lectured methods, and in particular comparing results of using different approaches. Matlab, Maple and Grif (the latter is a rather recent software for reliability assessment in use here at the NTNU) are used in relation to reliability analyses.

Maintenance optimization: