See the main Task Analysis page for background information https://abrisk.co.uk/task-analysis/
I realise that people sometimes struggle with knowing where to start with Safety Critical Task Analysis (SCTA). First the don’t know which tasks to look at and then they don’t know how to structure their analysis. Having a good operating or maintenance procedure can help, but unfortunately many procedure out there are not well structured and are not a good basis for analysis.
Something that bothers is projects where human factors people don’t do any task analysis because they are “waiting for the operating and maintenance procedures to be developed”, but by the time these become available time and/or budget has run out. This is crazy because the opportunity to influence the plant / equipment design is missed.
To help avoid these problems I have generated generic high level analyses for 15 tasks that I have encountered over the years. I have included the most common sub-tasks and task-steps, with a human error analysis showing some of the potential consequences. For the steps where an error could result in a Major Accident Hazard (MAH) I have indicated some of the most relevant Performance Influencing Factors (PIF).
None of these analyses will be complete or correct for any specific tasks you encounter, but they should provide an excellent starting point for discussion. If your task is not covered directly you may be able to take some of the subtasks instead and create a reasonable analysis. In many cases the basic structure of a task can be adapted (e.g. starting a pump will probably be a cut down version of the analysis for starting a compressor)
I have purposefully left the ‘Risk Controls’ column empty but added TBC (To Be Confirmed) alongside the steps associated with MAH. This is to prompt you to discuss how the risks of these steps are or will be managed. Even at a very early stage in a project, when there is very little information about the design and how tasks will ultimately be performed, discussing the MAH potential and the controls will be very useful.
I have provided an Excel file and PDF. The Excel will be most useful because you can filter columns and edit it to cover your requirements. I use a code for PIFs, which are shown in the task analysis job aid.
The tasks currently covered are:
- 1 Transfer fluid from tanker to storage (unload tanker)
- 2 Prepare a vessel for confined space entry
- 3 Start a fired heater
- 4 Export to ship
- 5 Start a compressor
- 6 Drain water from a tank
- 7 Recertify a Pressure Safety Valve (PSV)
- 8 Test diesel engine fire water pump
- 9 Black start (after total power outage)
- 10 Replace pipework
- 11 Safety Instrumented Function (SIF) proof testing (electronic simulation)
- 12 Leak test plant when re-instating after maintenance
- 13 Take high pressure gas sample
- 14 Start-up an oil/gas production well
- 15 Set-up for wire lining on an oil/gas well
Downloads:
Excel version https://abrisk.co.uk/wp-content/uploads/2024/05/Generic-high-level-SCTA-00.xlsx
PDF version https://abrisk.co.uk/wp-content/uploads/2024/05/Generic-high-level-SCTA-00.pdf
Task analysis jop aid (PIF codes) https://abrisk.co.uk/wp-content/uploads/2023/03/Task-risk-management-job-aid06.pdf