Process safety control barriers concept

One documented method uses process safety barriers identification for metrics selection. This concept uses a combination of lagging and leading indicators associated with process safety barriers and incident escalation controls to evaluate the process safety system performance. The basis for this method is documented in the U.K. Health and Safety Executive (HSE) publication HSG254 and illustrated by Figures 4.1-4.3. The strength of this technique arises from using the combination of indicators that provides multiple perspectives for judging the surety of a barrier or escalation control. For example, this basic concept was adopted and modified by BP to focus upon three information sources to assess key control barriers as summarized below ... 

Using this case study, the concepts derived in the previous Chapter will be enhanced to retrieve a structured way of analysing which in turn will be developed to retrieve the operational control structure of the company and the way safety barriers (measures) are affected by the control process in daily use. 

In the following sub-Sections the practical approach derived in the previous Chapter will be applied on this case study. Therefore, the precursors present inside the operational process are identified. Then, the control of the operational process will be modelled and analysed to find the ineffective control elements. Furthermore, the latent conditions causing the ineffective control will be retrieved and their impact on the existing safety barriers will be identified. Finally, improvement opportunities for the company will be indicated, together with some recommendations and enhancements for the applied concepts and the proposed practical approach. 

From the results of the case study it is concluded that the concepts presented are suitable for displaying the control process of an operational process and to partly identify control improvement areas. However, modelling an operational process with respect to control loops and affected safety barriers requires some additional refinements to the proposed concepts ... 

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