Management of Change (MOC) lies at the heart of a successful process safety management system. If a facility is properly designed and constructed then virtually all incidents are caused by someone, somewhere making a change and inadvertently taking the process outside its safe limits. This means, therefore, that, in order to have full control of a facility managers and process safety experts must have a clear definition of the word “change”. And one important part of understanding change in the context of MOC is having a clear grasp of what is meant by the term “temporary change”.
The following are features of a temporary change.
- The change has a timeline; at some point the system will revert to the prior state or else it is decided to make the temporary change permanent.
- Regardless of the duration of the change, its impact on safety and operability can be high. The facility that is being changed neither knows nor cares as to whether the change is temporary.
- Temporary changes to equipment or instrumentation are often made quickly and thus those making the change may be tempted to bypass the management of change (MOC) system.
- Many temporary changes are also emergency changes, but the two are not the same. An emergency change needs to be implemented quickly so there is justification for bypassing the MOC system. Such is not the case with a non-emergency, temporary change.
Temporary changes can lead to an attitude of, “let’s just get on with it — why bother spending hours conducting a hazards analysis, writing new procedures, training everyone involved and preparing an emergency plan for an activity that may take just a few minutes?”
Such an attitude is, of course, a recipe for trouble.
For example, the packing in a control valve may be leaking. So, it is decided to run a hose bypass around the valve, and to control the flow in the line using a manual valve, as shown below. The leaking control valve can then be blocked in and repaired.
This repair activity may take no more than 30 minutes. Yet it is a new operation, so the system has changed. Hence, the following steps should be followed:
- Conduct a safety analysis—probably using some type of What-If method. The analysis should focus on the feasibility of controlling the flow of chemical using a manually operated block valve.
- Write a temporary operating procedure.
- Train the operators in the new procedure.
- Prepare an emergency response plan in case the modification does not work properly.
- Make sure that the temporary hose is removed once the repair work is complete, that all valves are returned to their normal position and that blinds are installed.
These activities could take hours, far longer than the change itself, and so could easily engender the response, “Oh, let’s just get on with it—we don’t have time for all this bureaucracy.”
To which the response is . . .
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