MAP-01-011 HFI Technical Guide - Human Factors Integration ...

MAP-01-011 – HFI Technical Guide (STGP 11)• Disadvantages• The technique can be extremely time consuming. Typical HAZOPanalyses can take up to several weeks to be completed.• The technique requires a mixed team made up of operators: HumanFactors specialists, designers, engineers etc. Building such a team andmaking sure they can all be brought together at the same time is often adifficult task.• HAZOP analysis generates huge amounts of information that has to berecorded and analysed.• Laborious.• Disagreement within the HAZOP team may be a problem.• The guidewords used are either limited or specific to nuclear and petrochemicalindustry.• The human error HAZOP guidewords lack comprehensiveness.A3.10.2Event Tree AnalysisEvent tree analysis is a task analysis technique that uses tree like diagrams torepresent the various possible outcomes associated with operator tasks steps ina scenario. Event tree analysis can also be applied to human operations toinvestigate possible actions and their consequences.Event tree output is normally made up of a tree like diagram consisting of nodes(representing task steps) and exit lines (representing the possible outcomes).Typically, success and failure outcomes are used, but for more complexanalyses, multiple outcomes can be represented.Event tree analysis can be used to depict task sequences and their possibleoutcomes, to identify error potential within a system and to model team-basedtasks. In the early stages of a system design, event tree analysis can be used tohighlight potential error paths within a proposed system design, and can also beused to modify the design in terms of removing tasks, which carry a multitude ofassociated task steps.• Advantages• Event tree analysis can be used to highlight a sequence of tasks steps andtheir associated consequences.• Event tree analysis can be used to highlight error potential and error pathsthroughout a system.• The technique can be used in the early design life cycle to highlight tasksteps that may become problematic (multiple associated response options)and also those task steps that have highly critical consequences.May 2006 Page A3-90 Issue 4