Procedure-Based-HAZOP

In recent years, number of incidents due to inadequate or not having P&ID (normal) HAZOP review have been decreasing. On the other hand, about a half of all incidents occurred during shutdown, startup, maintenance and not normal operations. Root cause of these incidents is due to facilities reliability improvement, extended turnaround interval and/ or operator training related. Procedure-based-HAZOP review focuses on potential higher risk among operational tasks and procedural controls potentially having safety, health and environment (SHE) risks. Qualified procedure-based-HAZOP leader leads the review. At beginning of review, we discuss what is in each procedure and select higher risk procedures for further detail review. When the risk can be mitigated by hardware such as pressure relief valve, safety instrumented system, lock-out or tag-out, risks associated with procedure is judged not critical. During procedure-based-HAZOP review, previous HAZOP findings status is reviewed whether mitigation actions were adequate to mitigate the risk. Procedure-based-HAZOP leader is to read all the steps for selected procedure to discuss if the steps are clear for everyone, if steps are right order or if potential hazard is identified/ mitigated. Each site have standardized procedure writing format and the review also confirm if the procedure follows each site format. During the review, suggested correction is made by red color font. If further technical study is needed for the procedure change, normal HAZOP report form is used. Danger, Warning, Caution Signs according to recent ANSI Standards are used. Caution sign is used if equipment failure or loss of primary content be control by procedure. Warning sign is used if toxic gas release, fire or explosion (which potentially results in severe injury or death) be controlled by procedure. Benefit gained by doing procedure-based-HAZOP is that procedure is unified and operator can move one group to another group because procedure format is the same. We believe operator’s awareness of potential hazard and hazard control be improved by participating procedure-HAZOP discussion. Lesson learned from procedure-review-HAZOP are shared among refining and manufacturing sites. Examples that are identified during procedure-based-HAZOP is such as that minimum safe operating temperature is unclear, car-seal open lock-out action for safety valve inlet/ outlet valves is not written by steps, timing of shutdown sequence online timing is missing or using ejector where the vessel is not designed vacuum condition.