This recommended practice (RP) identifies leading and lagging process safety indicators useful for driving performance improvement and includes mechanical integrity related items. As a framework for measuring activity, status, or performance, this document classifies process safety indicators into four tiers of leading and lagging indicators. Tiers 1 and 2 are suitable for nationwide public reporting and Tiers 3 and 4 are intended for internal use at individual sites. Guidance on methods for development and use of performance indicators is also provided.
This RP was developed for the refining and petrochemical industries, but may also be applicable to other industries with operating systems and processes where loss of containment has the potential to cause harm. Applicability is not limited to those facilities covered by the OSHA Process Safety Management Standard, 29 CFR 1910.119 or similar national and international regulations. At co-located facilities (e.g. industrial parks), this recommended practice applies individually to the companies that own and operate the processes and not to the site as a whole. Events associated with the following activities fall outside the scope of this RP and shall not be included in data collection or reporting efforts:
- releases from pipeline transfer operations occurring outside the process or storage facility fence line;
- marine transport operations, except when the vessel is connected to the process for the purposes of feedstock or product transfer;
- truck or rail operations, except when the truck or rail car is connected to the process for the purposes of feedstock or product transfer, or if the truck or rail car is being used for on site storage;
- vacuum truck operations, except on-site truck loading or discharging operations, or use of the vacuum truck transfer pump;
- routine emissions that are allowable under permit or regulation;
- office, shop and warehouse building events (e.g. office fires, spills, personnel injury or illness, etc.);
- personal safety events (e.g. slips, trips, falls) that are not directly associated with on-site response to a loss of primary containment (LOPC) event;
- LOPC (loss of primary containment) events from ancillary equipment not connected to the process (e.g. small sample containers);
- quality assurance (QA), quality control (QC) and research and development (R&D) laboratories (pilot plants are included);
- retail service stations; and
- on-site fueling operations of mobile and stationary equipment (e.g. pick-up trucks, diesel generators, and heavy equipment).
Guiding Principles Performance indicators identified in this recommended practice are based on the following guiding principles.
- Indicators should drive process safety performance improvement and learning.
- Indicators should be relatively easy to implement and easily understood by all stakeholders (e.g. workers and the public).
- Indicators should be statistically valid at one or more of the following levels: industry, company, and site. Statistical validity requires a consistent definition, a minimum data set size, a normalization factor, and a relatively consistent reporting pool.
- Indicators should be appropriate for industry, Company, or site level benchmarking.
Sample Items of Interest to the Inspectioneering Community The document shows the relative position of mechanical integrity items within the scheme and covers reportable and measureable events and observations such as, but not limited to:
- Exceedences, excursions and violations of safe operating limits, which could include things like operating pressures, operating temperatures, integrity operating windows (IOWs)
- An inspection or testing result outside of acceptable limits The document states that, “(t)hese findings typically trigger an action, such as replacement-in-kind, repairs to restore fitness-for-service, replacement with other materials, increased inspection or testing, or de-rating of process equipment.”
Examples of Tier 4 Indicators
“6) Safety Critical Equipment Inspection—Percent of inspections of safety critical equipment completed on time. This may include pressure vessels, storage tanks, piping systems, pressure relief devices, pumps, instruments, control systems, interlocks and emergency shutdown systems, mitigation systems, and emergency response equipment.
7) Safety Critical Equipment Deficiency Management— Response to safety critical inspection findings (e.g. nonfunctional PRDs and SISs). This may include proper approvals for continued safe operations, sufficient interim safeguards, and timeliness of repairs, replacement, or rerate.
8) Management of Change (MOC) and Pre-Start-up Safety Review (PSSR) Compliance—Percent of sampled MOCs and PSSRs that met all requirements and quality standards.”
Table of Contents
1.3 Guiding Principles
2 Normative References
3 Terms, Definitions, Acronyms, and
3.1 Terms and Definitions
3.2 Acronyms and Abbreviations
4 Leading and Lagging Performance Indicators
5 Tier 1 Performance Indicator— Process Safety Event (T-1 PSE)
5.1 Tier 1 Indicator Purpose
5.2 Tier 1 Indicator Definition and Consequences
5.3 Calculation of Tier 1 PSE
5.4 Optional Tier 1 PSE Severity
6 Tier 2 Performance Indicator— Process Safety Events (T-2 PSE)
6.1 Tier 2 Indicator Purpose
6.2 Tier 2 Indicator Definition and Consequences
6.3 Calculation of Tier 2 PSE Rate
7 Tier 3 Performance Indicators— Challenges to Safety Systems
7.1 Purpose of Indicator
7.2 Examples of Tier 3 PSEs
8 Tier 4 Performance Indicators—Operating Discipline & Management System Performance
8.1 Purpose of Indicator
8.2 Examples of Tier 4 Indicators
9 Guidelines for Selection of Process Safety Indicators
9.2 Purpose of Indicators
9.3 Lagging versus Leading Indicators
9.4 Characteristics of Effective Indicators
9.5 Selection of Indicators
10 Reporting Performance Indicators
10.1 Format and Forum
10.4 PSE Data Capture
Annex A (informative) Examples
Annex B (informative) Listing of Chemicals Sorted by Threshold Quantity
Annex C (informative) Decision Logic
Introduction (excerpt from the RP)
Process safety incidents are rarely caused by a single catastrophic failure, but rather by multiple events or failures that coincide. This relationship between simultaneous or sequential failures of multiple systems was originally proposed by British psychologist James T. Reason  in 1990 and is illustrated by the “Swiss Cheese Model.” In the Swiss Cheese Model, hazards are contained by multiple protective barriers each of which may have weaknesses or “holes.” When the holes align, the hazard is released resulting in the potential for harm.
Christopher A. Hart in 2003  represented Reason’s model as a set of spinning disks with variable size holes. This representation suggests that the relationship between the hazard and the barriers is dynamic, with the size and type of weakness in each barrier constantly changing, and the alignment of the holes constantly shifting.
API RP 754, PROCESS SAFETY PERFORMANCE INDICATORS FOR THE REFINING AND PETROCHEMICAL INDUSTRIES, 1st Edition, March 2010
For more information or to purchase the RP (recommended practice) visit the API web site at www.api.org