Writing emergency procedures can be an arduous and tedious task. Volunteers are usually few and far between when the procedures need to be updated and revised. People who eventually end up with the task often have little experience in technical writing and do not consider the various formats in which procedures can be written.
Formatting of emergency procedures is an often overlooked step in the procedure revision process. The first step to writing procedures should be choosing a format that will accommodate the activities in the procedural steps. For example, if a particular process has specific steps that must be accomplished in exactly the same sequence, then a tabular format is usually found to work best. Process units that have shutdown systems, such as catalytic cracking units, are likely candidates for the tabular format.
Other process units have more complex interactions, and the tabular format becomes unwieldy due to the fact that the length of the procedures must be increased dramatically to account for all of the variations in the procedural steps. An example of this situation would be a hydroprocessing plant, where hydrogen of different purities must be shared between units. For this set of circumstances, the procedures must account for the myriad ways the hydrogen must be routed between the units for various emergency situations. In this instance, a flowchart format usually works best.
Flowchart formats are in common use in the nuclear industry. One recent study ("Flowchart-Format Emergency Operating Procedures-Strengths and Weaknesses", 14th Biennial Conference of Reactor Operating Experience Plant Operations: The Human Element, Aug. 1989) examined some of the strengths and weaknesses of using the flowchart format. There were three reported advantages: 1) they allow the operator to perform several procedures simultaneously, 2) they allow the operator to maintain an overall sense of plant status, and 3) they support decision making by the operators. The only disadvantage found was that the size of the flowchart is sometimes excessive for longer procedures. If the flowchart format is used, researchers suggest that a table be available on which to lay the procedures.
Beville Engineering has found similar results when implementing the flowchart format for unit emergency procedures. In one case, flowchart format reduced the number of emergency procedures from 10 to 1. The one procedure fit on a 7 by 18 inch piece of paper with good legibility. Beville also found that the flowchart format aided in situations where one control operator would operate several units. If the control operator is operating 3 processes with 6 procedures each (for a total of 18 procedures), then procedure reduction becomes a significant factor.
As mentioned previously, the best format for a set of procedures depends on the tasks to be done. If the tasks are complex, and many of the steps are interdependent, then the flowchart format is probably best. If the tasks to be done are sequential and invariant, then the tabular format is the best choice.
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