Sequentially timed events plot investigation

The sequentially timed events plot investigation system (STEP)... 

The first case study describes the application of the sequentially timed event plotting (STEP) technique to the incident investigation of a hydrocarbon leak accident. Following the analysis of the event sequence using STEP, the critical event causes are then analyzed using the root cause tree. 

This case study concerns the events leading up to the hydrocarbon explosion which was the starting point for the Piper Alpha offshore disaster. It describes the investigation of the incident using the sequentially timed events plotting (STEP) technique. Based on the STEP work sheet developed, the critical events involved in the incident are identified and analyzed in order to identify their root causes. 

In order to accurately describe the actual sequence of events that make up the accident techniques such as STEP (sequential timed event plotting—see Chapter 6 and the case study in Chapter 7) can be used by the investigator. 

The heart of the book is its presentation of Sequentially Timed Events Plotting (STEP). The accident investigation methodology presented relies on a new conceptual framework, building on system safety technology and the safety assurance systems of MORT (management oversight and risk tree). 

After having set the stage of the workshop, an overview of the case and the decision criteria for riser disconnection were presented. This was followed by a presentation of the STEP-analysis, i.e. Sequentially Timed Events Plotting (Hendrick and Beimer, 1987) as a method to analyse scenarios. STEP-analysis is an accident investigation method involving a detailed mapping out of a scenario (accident) by plotting the... 

The situation was analysed by the STEP investigation method (Sequentially Timed Events Plotting, see Hendrick Benner, 1987). The STEP diagram is shown in Figure 1. 

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