As Dennis Hendershot quoted [1] ‘‘You can’t manage what you can’t measure.’’ An important question that has been on safety professionals’ minds for decades is ‘‘how to measure process safety performance.’’ Often, the answer to this question was downplayed and process industries often relied on many indicators such as loss time injuries, fatal accident rate, OSHA incidence and fatality rates, and lost work days. Although these indictors served a purpose (measuring the after effect in the form of loss, injury, work days, etc.), no attempt was made to investigate the source of these losses.
Measuring injuries to people or lost work days are only one aspect of measuring safety performance and it is often considered to be part of occupational or personal safety measurement. However, the focus of process safety management is to prevent release of hazardous material or energy from the process equipment. Therefore, process safety measurement needs to include process safety causes of concern and the end effects in the form of incidents, injury, lost work days, and/or financial loss. As rightly pointed out by Hendershot, incidents involving release and subsequent fire, explosion, or toxic cloud that causes no human injury or loss of work days still represents significant failure(s) of process safety management systems and needs to be accounted to evaluate the process safety performance of a manufacturing plant [1].