What’s in your PM program?

By Ian Verhappen, PE, CAP, and Herman Storey

There are so many acronyms and so little understanding of what they mean. Not only do we have to interpret acronyms that are specific to our industry, the automation discipline, our companies, and what is perceived to be “common knowledge” across multiple sectors, but the expectation is that we do so consistently. These are tough tasks, for which this article will give you pause for thought and the impetus to contribute to the discussion, so we can standardize at least some of these concepts.

Keeping in mind that “project manager” is not the “PM” we are considering, the table shows a number of maintenance-related PM terms that could have the corresponding meanings. We suggest alternate abbreviations to reduce confusion. We encourage comments on these in hopes that we as an automation community can get closer to a common understanding and definition of each of the terms. Only one of the definitions is presently accepted by industry, as reflected in the referenced International Electrotechnical Commission (IEC) standard.

Unfortunately, even if we could agree on these definitions and their associated acronyms, the respective term would describe only a small part of the complete set of activities that encompass the full life cycle of configuration and system tools support, parts management, scheduling, maintenance activity, and follow-up, including determining why the maintenance is required.

Fortunately, work is being done to help define how to do effective maintenance for intelligent field devices. The ISA108 standards committee, Intelligent Device Management (IDM) (www.isa.org/isa108), is developing a series of documents to define the full life cycle for intelligent devices. IDM is a much better expression of the asset management requirements for intelligent devices than any of the limited and confusing PM terms.

Because IDM addresses the full life cycle, any associated program cannot focus only on the maintenance aspect of the device and associated support infrastructure, but must begin at the onset of the design process and continue through to the retirement or replacement of the device.

The intelligent device life cycle is obviously much shorter than that of a facility, yet longer than a typical run between facility maintenance outages. Consequently, the various life cycles must also be coordinated, as the IDM program must coordinate with other elements of the business and control systems. There are many other standards-related activities within ISA, the IEC, and the International Organization for Standardization that exist or are in development to identify and bridge the “gaps” between not only the various systems, but also between the associated work practices to execute the tasks necessary to support intelligent devices throughout their life cycles.

Your PM program may be passive, preventative, predictive, proactive, or something else entirely, but regardless of the name, it represents but one part, although an important one, of the full life cycle of your automation system and facility.

Passive maintenance

This term is characterized as a condition of not responding to events by deferring action entirely. Many individuals may interpret this as breakdown maintenance.


As of February 2015, IEC 192-06-05 defines this as “maintenance carried out to mitigate degradation and reduce the probability of failure.”

Unfortunately, most of us believe this is the reason for doing any form of maintenance and instead interpret the definition as “generally applied to maintenance done on a fixed schedule that has not been optimized through the analysis of failure history.”


Repairs are made to minimize future likelihood or effects of failure, including the use of diagnostics and reliability-centered maintenance techniques to lower failure rates.


Predictive maintenance is the use of inspection and testing triggered by failure-rate analysis of the equipment being maintained and an assessment of the failure consequences to anticipate future conditions and events. Some standards also include diagnostics within this term, even though many diagnostics are not predictive.


About the Authors

Ian Verhappen, PE, CAP, is an ISA Fellow, FS engineer (TÜV Rheinland), and managing director of the ISA108 committee.

Herman Storey is co-chair of the ISA108 and ISA100 committees. He is chief technology officer of HE Storey Consulting based in Kingwood, Texas.

Your Thoughts

Please feel free to send your thoughts about this topic to Bill Lydon at InTechmagazine@isa.org.