Safety case benefits

The book does not focus on occupational safety and health issues, although improved process safety can benefit these areas. Detailed engineering designs are outside the scope of this work. This book intends to identify issues and concerns in batch reaction systems and provide potential solutions to address these concerns. This should be of value to process design engineers, operators, maintenance personnel, as well as members of process hazards analysis teams. While this book offers potential solutions to specific issues/concerns, ultimately the user needs to make the case for the solutions that provide a balance between risk... 

Any risk-benefit analysis should be clearly set out in the safety case with the appropriate justification, rationale and supporting evidence. The complexity of the arguments involved warrant close cooperation between manufacturers, users and regulators. In most cases the inclusion of potential benefits in the safety case is simply not required in HIT CRM and, if anything, introduces subjective noise into an otherwise objective methodology. 

Safety cases are gradually being adopted in the HIT domain especially in the UK in order to comply with safety standards ISB 0129/0160 [7]. Outside the UK the term safety case is not widely used [8] but nevertheless reports which achieve the same purpose are becoming increasingly prevalent and may take other names such as a Safety Analysis Report. The safety case and its development has a number of benefits to manufacturers, healthcare organisations and ultimately to patients. These can be broadly categorised as [9] ... 

There are at least of a couple of other subtle benefits of the safety case. For manufacturers, products which are delivered along with a well thought-out safety case create a perception of quality, attention to detail and responsibility. The value which this adds to a product is very real and can generate a competitive edge over products from alternative suppliers. Manufacturers are quite justified in marketing the fact that a product has been subject to a safety assessment particularly where there is a statutory or regulatory requirement to comply with a standard. 

HSE (2003) Literature Review on the Perceived Benefits and Disadvantages of UK Safety Case Regimes. UK Health and Safety Executive Norwich. 

A significant amount of effort has been put in the development of a graphical tool called Goal Structuring Notation (GSN). The Computer sciences department at York University have been developing this graphical tool to support safety cases in the aerospace and railway industry as it is presented in [Weaver, 2002] and [Weaver, Despotou, et. al, 2005]. Whilst there are many benefits, the tool does not provide a quantitative assessment as to how much processes influence one another. 

Even where this approach is not mandated, there can be significant benefits for safety case developers obtaining feedback from regulators early in the lifecycle concerning the proposed argument approach. 

The scope of the Safety Case is to include an assessment of the impact of the modification on the safety of the whole aircraft It is of course of no benefit to show that the new system is acceptably safe without also considering the effects it has on the platform into which it is integrated. 

A further benefit of GSN was realised when it came to asking equipment suppliers for sub-system safety cases. The diagrams showing the breakdown of hazards related to system functions formed an easy starting point for helping each supplier to identify their contributions to the safety case. Various parts of the process argument were also used to show the relationships between different organisations safety activities. 

At various stages throughout the creation process. Safety Case reviews were undertaken. Again, the benefits of GSN became clear during these reviews. At one point, the near-complete document (comprising 26 pages of GSN diagrams) was presented to representatives from the MoD at the project PDR. This took just 30 minutes. 

We have limited our discussion in this paper to safety cases, but the concepts apply immediately to any property of interest. Thus, for example the notions of assured security cases or assured reliability cases are appropriate, and each would benefit from the explicit introduction of a confidence argument in the same way that a safety argument does. Naturally, the content of an assured security case would differ from the content of an assured safety case, but the overall structures and approaches would be identical. 

There appear to be a number of benefits from adopting this viewpoint. The chief one is that it makes very clear that a questioning, ehallenging attitude towards the safety of a system is expeeted even when there is a safety case that claims to show that the system is safe. 

Development of the methodology supporting the generic activities of safety risk analysis and management process for any system would bring benefits to the industry. Moreover, since the current practice in the UK is that demonstration of conpliance with the ALARP principle is structured in the form of a Safety Case, the process also needs to support the development of the Safety Case. 

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