Experience Transfer Stories 02 –Functions, Task, and Workload Assessments for Process Plant CCRs.

Existing process plants undergo modifications at various stages in their life cycle. These modifications include various additions to their CCR (central control room) functions. Often these changes are perceived as minor. However, these changes over time adds up and gradually increase the workload of the CCR operators. Therefore, it is important to conduct Functions, Tasks, and Workload assessments for the CCR as part of every process plant modification project. The failure to do that will result in an overloaded, stressed, ans non-optimal CCR which then can easily lead to accidents initiated by human error, OR leads to making wrong responses to a developing incident.

Figure below shows a typical (but simplified) Functions and Tasks Assessment template used often in the North Sea Oil and Gas sector. As can be seen there, each new modification scope (i.e. new process units or equipment) is separately analyzed with respect to its CCR scope (functions). The CCR operators work tasks at different operational modes with respect to that unit (such as start up, normal operation, process upsets, shut down, cleaning, switch-over, maintenance, etc.) are separately recognized. At the end of this exercise carried out in a workshop with the participation of key discipline design engineers as well as plant operators and plant management, a clear picture emerges with respect to the additional CCR functionalities and work tasks created by the modification scope. Now, from this point onwards, it is easy to recognize the additional work loads. Based on that, and also considering the available resources, decisions can be made to either increase the existing manning level at CCR, or to introduce more automation in the process design. The decisions are then in turn fed back to the engineering design team to implement in the plant modification design.

The responsibility of correctly conducting this Functions, Tasks, and Workload assessment rests with the Safety Engineering & Management discipline. Also ensuring proper participation of required engineering design disciplines (Process, Instrumentation, Electrical, HVAC, Piping, etc.) and other resources (plant operators, management, safety delegates, etc.) in the workshop is a part of this responsibility.