Carrying Out a Study
This chapter describes the preplanning of a study, especially the leader’s interaction with the client, illustrated with a list of 20 aspects to be considered in advance; detailed arrangements for the team meetings; the initial meeting and the routine detailed study meetings; responsibility for actions generated by the study; collecting and reviewing the responses; completing and signing off the study report; follow-up of actions and management of change.
Keywords
Pre-planning for client; meeting planning; action responses; signing off; action follow-up; management of change
6.1 Premeeting with Client
It is important that the HAZOP team knows what is required of it, and the Client (Project) has had an opportunity of discussing this with the team. This is particularly important when the Facilitator is an external consultant.
The starting point of the HAZOP should be a meeting between the Client and the Facilitator. During this meeting, there should be a discussion such that the Facilitator knows what the Client requires from the HAZOP and what can be delivered (“the Deliverable”). It is quite possible that each Client will have specific requirements. This meeting should prevent any possible misunderstanding which may affect the quality of the final deliverable. This meeting should draw up a Scope and Terms of Reference.
Consideration should be given to the following when defining the Scope of the study:
• The start and end points, which might be outside the immediate P&IDs (particularly for a modification or a plant in a sequence of many).
• That which is included and that which is excluded from the study. For example with a modification some operability issues may already be recognized by Operations. Should they be noted? Likewise should any “mothballed equipment” be inside or outside the scope bearing in mind that it could be brought back into operation without further analysis?
• The likely Parameter and Guideword Matrix to be used.
• Any particular issues that the Client feels might require special attention.
• The availability and competence of future team members.
• In the case of a modification, the boundaries of the study both up- and downstream of that change.
• In the case of a modification, the Facilitator should satisfy him/herself that the P&IDs are of “Approved for HAZOP” quality. In the case of a modification, the Facilitator should satisfy him/herself that any interconnecting drawings (such as services) are both available and to the correct standard.
• The requirements or otherwise for risk ranking (outside the study) and against what criteria.
It is vital to note the status and revision of the information (e.g., procedure or drawings) to be used as the basis for the study as close out of actions normally requires them to be updated and significant changes may necessitate re-HAZOP.
Equally it is vital that team membership is limited to those who can contribute constructively and can contribute without external interference.
Consideration should be given to the following when defining the Terms of Reference:
• The method to be adopted (corporate or other).
• The recording format, spread sheet or other computer-based systems.
• In the case of a modification, how potential issues identified outside the immediate bounds of the study should be handled, recognizing that causes could be within the scope but that the consequences identified may be outside the scope of the system under review.
• The delivery date and reporting format. This must take account of how the actions will be passed on and tracked. It is good practice to ensure that the reason for any recommended action can be understood when that line of the HAZOP study record is read in isolation.
• The requirements for the follow-up HAZOP Study following resolution of the actions.
Finally, the Facilitator should have a view of the room to be used for the study and to satisfy him/herself that:
• the room is a suitable size allowing the tables to be arranged to the Facilitator’s preference (e.g., horseshoe, round, or conference style);
• the heating/air conditioning, lighting, and ventilation are adequate;
• there is sufficient display space for large-scale drawings and adequate storage for supporting information such as line lists, pipe specs, and data sheets;
• there are sufficient power points and projection screen or a suitable wall area;
• there is communication from the meeting room but not necessarily to it. Wi-Fi links are useful to allow internet access to reference material;
The facilitator may also wish to review the general support arrangements for the study such as the availability of the members and possible alternates, the travel and accommodation arrangements for those from off-site, and the possibility of changes to P&IDs during long studies.
6.2 Planning the Meetings
The first requirement is a good estimate of the number of meetings required for the study. This can be made once the boundaries for the study are defined and the preliminary planning work, including the selection of the stages, has been done. The length of time needed to analyze a section or stage depends on its size, complexity, and the associated hazards. Experience from similar studies provides a good guide to the length of time to be allowed and hence the number of meetings needed.
An ideal arrangement is to have no more than three or four sessions a week, each limited to half a day. This is often impractical, however, and many studies are done as a full-time activity. In this situation, the leader must monitor the team’s performance to ensure an acceptable standard is maintained. There should be an arrangement that allows all the team members to work from central documentation. Regular short breaks are advisable and interruptions to meetings should be prevented except for emergencies.
Team members should be provided with background details of the planned study in advance of the first meeting. This should include details of the scope and purpose of the study, essential design information, and an indication of the HAZOP approach to use, including a first list of guidewords and parameters. Normally, the team membership and details of planned meetings are included.
Full details of options and methods of recording are covered in Chapter 7. It is helpful to have a standard template for recording to ensure that none of the intended entries are overlooked. The style of recording should have been agreed at the premeeting (see Section 6.1), and the whole team should then be briefed.
6.3 The Study Meetings
6.3.1 The Initial Meeting
In a long study, the first meeting differs from the bulk of the working meetings. After a reminder of the study objectives and scope, a brief overview of the project should be given, preferably by the individual most closely associated with the development work. This should cover the plant and intended operations as well as its relationship to the site, the services, and neighboring units. For a reaction system, the overview includes the process chemistry and basis for safe operations. It may be useful to give a short review of the HAZOP working method adopted, including discussion of the guidewords and parameters. This is particularly important if the Project is in any way out of the ordinary. Any queries about the precirculated material can be dealt with. This preliminary discussion aims to ensure the team has a common understanding of the project and it helps to establish the group as a functional team. It is also an opportunity for team members to learn of the skills and special competencies of each other.
If the team members have not worked together before, it can be helpful to discuss and agree a set of “ground rules.” They may range from behavioral aspects such as listening to others, giving everyone a chance to speak, and not having simultaneous conversations to technical aspects such as how they will help the scribe and whether solutions will be sought to the problems identified. To be effective they need to be accepted (“owned”) by the members although the leader, probably having most experience of HAZOP study, may suggest many. Working within the rules is best done by self-discipline of the members but the leader may, at times, have to remind the team of them.
6.3.2 The Detailed HAZOP Study Meetings
These follow an agreed plan, working as described in Chapter 4, concentrating on the identification and recording of potential problems for all SHE hazards and, if agreed, operating problems as well. It is recommended that the project’s process engineer suggests a design intention for each section or step and specifies the safe design envelope for operation. The team can then discuss the design intention and refine it if necessary. The extent to which the problems are evaluated, ranked and solved, varies according to company policy and requirements. In the planning and definition of objectives for a study, it must be made absolutely clear what the responsibility and authority of the team is in these respects as failure to do so results in confusion and wasted time within the meetings.
There should be periodic reviews of the work, either at the completion of a section or stage or at the end of a meeting. As well as confirming the recorded details of the analysis, this encourages a check upon the progress of the study against the study plan. Reasons should be sought for any significant deviation. If ranking of frequencies or consequences is to be done, then the most efficient way is to do this is at the end of a session. Similarly, this is probably the best time for an outline discussion of SIL ratings if this is required. The whole team should receive a copy of the meeting records for checking as soon as possible after the end of a meeting in addition to any action notes assigned to them.
6.4 Coordinating and Reviewing Responses
The need to receive, check, and incorporate action responses arises as a study progresses. In a short study, this may be done at a special meeting after the whole study is complete. In a long study, it is normally done by periodically using part of a meeting to review the responses, after which they can be incorporated into the formal final record.
It is essential that when a recommendation for change is accepted, whether a hardware or a software change, the team agrees that it is an adequate solution to the original problem and also that it does not cause further problems by introducing new deviations. However, responsibility for the accuracy and adequacy of the response lies with the individual to whom the action was assigned, not the team. The responses generated from the action sheets should not be accepted unless they provide sufficient detail of their basis, including any necessary calculations, references, and justification for the proposal. These will become part of the HAZOP study records and hence will be part of any audit or review to show complicity with regulations.
Where a response generates significant design or operational change affecting the design intent then it may be appropriate to HAZOP study these as well.
6.5 Completing and Signing Off the Report(s)
The simplest and most common definition of completion for a HAZOP study is when all of the selected plant and operations have been examined and all of the problems identified during the examination have been considered. This includes collection of the responses and actions, and review and acceptance by the team (or by an authorized person or subgroup) as a satisfactory response to the identified problem. At this point a delegated person signs the detailed HAZOP study report as complete, that is, that responses have been received for all of the actions and that these have been reviewed and are considered to be satisfactory. It does not mean that all the recommendations have been carried out—that has to be covered under a separate management procedure. In major studies, the signing off may be staged. If a few responses remain outstanding, it is still possible to sign off the remainder provided company procedures include a secure follow-up mechanism. In this case, it is advisable that each outstanding action is allocated to a category—for example, to be done before start-up or may be completed during commissioning and so on.
6.6 Follow-Up of Actions and Management of Change
Responsibility for the implementation of actions, including any rejections, passes to the line management for the project, where an authorized person has the responsibility for signing off the actions as they are implemented. Although individual members of the team may have responsibilities for the implementation of some actions, the team as a group should not. If an action is rejected, the records should include the reasons for this, including a signed authority. There should be a formal check before the facility is commissioned to ensure that all actions identified during the study have been implemented or resolved. An established tracking system for actions is needed on major projects, and it may be done as part of a computer-based HAZOP recording package.
Once the HAZOP study is complete, it is important to introduce a system to minimize and control any further changes to the design. The implications of such change to the safety of the process must be considered by a structured Management of Change Procedure and, in some circumstances, it may be necessary to reconvene all or part of the HAZOP team.
The management of change must be a live system which captures and tracks all changes both before start-up and through the operational phase of the project.
It can also be beneficial to conduct a follow-up review, perhaps 12 months after the study, to draw out the “lessons learned.” Beneficial changes can then be used to improve the Corporate Design Guides as in HS 2 (see Chapter 2).