An essential element of any improvement program is the measure of existing and future performance.
Therefore, to continuously improve upon process safety performance, it is essential that companies in the chemical and petroleum industries implement effective leading and lagging process safety metrics.
This document describes the recommendations assembled by the Center for Chemical Process Safety (CCPS) Process Safety Metric committee for a common set of company and industry leading and lagging metrics.
Within this document is a description of three types of metrics:
“Lagging” Metrics – a retrospective set of metrics that are based on incidents that meet the threshold of severity that should be reported as part of the industry-wide process safety metric.
“Leading” Metrics – a forward looking set of metrics which indicate the performance of the key work processes, operating discipline, or layers of protection that prevent incidents.
“Near Miss” and other internal Lagging Metrics – the description of less severe incidents (i.e., below the threshold for inclusion in the industry lagging metric), or unsafe conditions which activated one or more layers of protection. Although these events are actual events (i.e., a “lagging” metric), they are generally considered to be a good indicator of conditions which could ultimately lead to a more severe incident.
These three types of metrics can be considered as measurements at different levels of the “safety pyramid”. The pyramid is divided into four separate layers (Process safety incidents, Other incidents, Near miss, and Unsafe behaviors/Insufficient operating discipline), it is easier to describe metrics in terms of the categories shown above.
It is strongly recommended that all companies incorporate each of these three types of metrics into their internal process safety management system. Recommended metrics for each of these categories are included in the three primary sections of this document.