INTRODUCTION

ISO 9000 is a powerful quality standard, but it is possible to follow it in many areas, including HAZOP Studies, without more than a marginal improvement in the quality of the activity. The basic difficulty that we face in trying to design a quality system to match the HAZOP activity is that the study procedure relies on brainstorming. Even though the guidewords used in HAZOP methodology provide structure to this brainstorming, they do not of themselves ensure that the brainstorming process will produce quality results.

Before DNV Technica could use ISO 9000 to assure the quality of HAZOP Studies, we needed to define a measure of the quality of a study. This in turn required a definition of the objectives of a HAZOP Study. The definition we chose is as follows:

The objectives of a HAZOP study are:

1. To identify all potential causes of process upset scenarios which could lead to significant safety or operability consequences.
2. To decide whether the current design ensures that the risk from each identified scenario is at a suitably low level.
3. If not, to recommend modifications which will reduce the risk to a suitably low level, or specify a further study to investigate the issue, with the objective of identifying a suitable modification.

Unfortunately, this objective set may be sufficient for a consulting company, only responsible for the conduct of the HAZOP Study itself, but it is incomplete for the client company because it does not put HAZOP in the context of a Safety Management Program. We decided to look beyond the HAZOP itself, to the reasons for carrying out the study, and the objectives for the process unit under study.

This then introduces more objectives, which may be the following:

1. To maximise the value of the facilities to the company by reducing process related risks to tolerable levels and to improve operating efficiency.
2. To recommend cost effective risk mitigation measures in line with company targets.
3. To recommend cost effective measures which will improve the profitability of the operation.

These two sets of objectives then allowed us to put forward quality criteria for a specific HAZOP study, bearing in mind that the client company will require a framework policy to regulate when HAZOP studies will be carried out on what facilities. The HAZOP Study quality criteria we have adopted are:

1. All potential scenarios leading to significant safety or operability issues will be identified.
2. Decisions will be made on the acceptability of the risk level from each of these scenarios.
3. Where the risk is intolerable, recommendations for change will be made which will bring the risk level within tolerable limits.
4. Recommendations will be implemented as rapidly as feasible, when justified against client company criteria.
5. An authorised rejection notice will be produced to explain the background to the rejection of any safety recommendation.

It was then necessary to decide which factors could influence these quality objectives, and how our quality system could ensure their achievement.

In addressing these quality objectives, DNV Technica identified the following factors of importance: