A major concern of companies operating refineries, gas and chemical plants is continued assurance of plant integrity. Plant integrity is loosely defined as assurance that there will be no "loss of containment", that all safeguarding systems act in the desired manner at the proper time and that the equipment is being operated within predefined limits, not necessarily design limits, that are necessary to assure continued operation from one major shutdown to the next. There are two approaches to managing plant integrity, the first being a reactive approach which tends to correct threats to integrity as they occur and the second being a "business process" approach. The business process approach to managing integrity is a proactive way of managing integrity in which failure modes are anticipated and the proper safeguards are put in place to prevent degradation or failure. In most cases, a combination of the two approaches is necessary to bring a plant back to the original level of integrity. The reactive mode is for correcting known problems and then business processes must be implemented in order to prevent future deterioration of plant integrity. Typically, an integrity review for a plant is carried out over 2 - 3 weeks by a multi-discipline team of technical experts well versed in the development and application of business processes.

Typical business processes that have been developed for managing integrity include the following:

  • Risk Based Inspection (RBI) which defines the interval between inspection of vessels and piping thus assuring that the more critical pieces of equipment are inspected over shorter intervals and less critical pieces over longer intervals.

  • Defect Elimination, which is a process that captures incidents, determines the root cause with a structured root cause analysis and then based on business premises, establishes the best solution for the problem.

  • Competency Assurance, which assures that personnel who operate and maintain the plant meet minimum standards of competency appropriate for the job they are doing.

  • Integrity Operating Windows, which is a process, associated with RBI that defines the allowable limits of operating variables (not mechanical design limits) for critical equipment such that operation within the limits assures integrity for the interval between inspections.

A thorough understanding of the fundamentals of Risk Management forms the basis of most of these business processes and is therefore also a critical ingredient of modern integrity management.


Shell Global Solutions, International (Shell GSI), is a technical organisation consisting of approximately 2500 staff with the main offices in The Netherlands (Amsterdam and The Hague) and Houston with additional offices strategically located around the globe. Shell GSI provide technical, project, HSE and consultancy services not only to Shell operating companies around the world, but also to non-Shell companies including many of the state owned oil companies throughout the world. The Shell GSI consultancy organisation exists as an integrated group of over 200 staff providing consultancy services in the areas of Hydrocarbon Management, Asset Management, Health, Safety and Environment Management, Operations Management and Benchmarking.

The Asset Management specialists provide a range of maintenance, reliability and integrity services and have an extensive international customer base including many in the Arabian Gulf region.

Although Shell Global Solutions is a relatively new organisation (in existence approximately 5 years), one trend that has become apparent in the past few years is an increased interest in improved "Plant Integrity" by Shell and non-Shell customers alike. A number of recent high profile incidents involving loss of containment with resultant fires, loss of life and damage to assets seems to have precipitated some of this increased interest.