Risk Evaluation in Real Time or Off Line

Often a HAZOP team will contain the people with all the practical knowledge necessary to make a risk assessment. In fact, this is exactly the team best able to carry out a study. For many of the risk scenarios identified it is not necessary to use Quantified Risk Analysis techniques, and deferring to a specialist team may be counter-productive. In these circumstances a simple risk index approach can be used, incorporating the Delphi technique to remove individual bias. Such techniques are described in many papers and text books.^[2] The advantage of the Real Time approach is that it is not very time consuming, but it trains the team in making judgements. This means that they do not often need to use the full risk index technique!

When the team identifies a scenario with very serious potential consequences, no risk index technique will adequately evaluate it. In these circumstances specialist help is almost always necessary, and QRA is the option of choice. This is necessarily an Off Line activity.