How to perform alarm rationalization

Remember that the system on which you are implementing the alarm rationalization can affect the outcome. Such things as prioritization scheme, alarm filtering, screen organization, alarm presentation, documentation capabilities, alarm procedure capabilities, and other alarm capabilities of the control system will impact some of what you can do in your alarm rationalization.

Also, third-party software products for some control systems can enhance your alarm capabilities, but poor application can give you a worse system than you started with.

8.  Benchmark the New Alarm System
Once the alarm rationalization is implemented, benchmark the final product to determine the success of the rationalization effort. (It also makes management happy to see the results of a successful project--they like numbers.) Do this by determining the alarm system benchmark metrics identified in step 2 using the same methods as used in step 3.

Don't forget the operators and operating staff interviews. These people will know about improvements that the mathematical benchmarking will not tell you.

Life After Rationalization
A good audit process is necessary to ensure your alarm system stays manageable and in control. Online dynamic alarm monitoring systems can assist in this. If you are not following a comprehensive alarm management procedure, your alarm system may go out of control again in the future.

There are great opportunities for improvement in our alarm systems. Due to their complexity, alarm rationalization requires careful planning and organization and is generally a team effort.

The market for alarm management and rationalization products is still underdeveloped but the marketplace is growing with improvements by control system manufacturers and third-party products. This is being driven by more and more people realizing that there are issues and problems with their alarm systems as well as opportunities leading to the desire to optimize their alarm systems.

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Few Solid Guidelines

There are not a lot of solid guidelines in the area of alarm management/rationalization. Probably the best known is the British Engineering Equipment and Materials Users Assn. (EEMUA), which has a guideline, "Alarm Systems, a Guide to Design, Management and Procurement, EEMUA Publication No. 191." This guideline has some metrics for good performance of an alarm system.

The British Health & Safety Executive (HSE) also has a couple of guidelines that may be of some assistance (see "Better Alarm Handling," and the Technical Measure Document, "Control Systems."

ISA offers ISA TR91.00.02, "Criticality Classification Guideline," which provides guidance in defining types of systems, as well as ANSI/ISA S18.1 1992, "Annunciator Sequences and Specifications."

IEC has IEC 61508, "Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related Systems," and IEC 61511, "Functional Safety: Safety Instrumented Systems for the Process Industry Sector," which address safety-related and safety instrumented systems that may have some application where credit is taken for alarms during risk assessment.

The Abnormal Situation Management (ASM) consortium of major companies has done considerable work in abnormal situation management and has a number of good articles.

Another good presentation on alarm systems is "Useful and Usable Alarm Systems: 43 Recommendations."

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Suppliers Exist

There a number of suppliers and the market is growing for alarm management and rationalization products and related services. The key is to find the products, services, and experience that most closely match your in-house capabilities and philosophy.

Some of the companies that supply alarm management and rationalization products and/or services (in alphabetical order) are Control Arts, Exida, Honeywell, Matrikon, Process Automation Services, Process Systems Consultants, and TiPS.

There also are some companies that provide expert systems for improving the operator decision process and detecting developing problems before the alarm stage, thus reducing the alarm load. Examples are Gensym and Nexus Engineering.

Many DCS and SCADA systems and vendors provide alarm management features or products. It generally is more cost-effective to use whatever features your system provides rather than a third-party add-on. However, some of these are somewhat primitive and don't provide the necessary functionality by themselves, though they are generally improving.

There also some add-on alarm products on the market that enhance a control system's basic alarm capabilities by providing online alarm management (alarm controls, alarm parameter management, alarm documentation, alarm system auditing, change control, etc.), alarm filtering, cause-and-effect analysis, alarm patterns, and dynamic reconfiguration of the alarm system for varying operating conditions.

References:

1. Johannes Koene & Hiranmayee Vedam, "Alarm Management and Rationalization," Third Annual Conference on Loss Prevention, 2000.

2. A. Nochur, H. Vedam, & J. Koene, "Alarm Performance Metrics," IFAC 2001.

3. Edward Marszal, "The Longford Gas Plant Explosion: Could Alarm Management Have Prevented This Accident?" Exida, 2003.

4. W.H. Smith, C.R. Howard, & A.G. Foord, "Alarms Management--Priority, Floods, Tears, or Gain?" 4-sight Consulting, 2003.

5. Yoshitaka Yuki & Kimikazu Takahashi, "Event Analysis Based on Causal Relation of Events, Alarms, and Operator Actions," ISA, 1999.

6. E.H. Bristol, "Improved Process Control Alarm Operations," ISA, 1999.

7. Yoshitaka Yuki & Jim Parks, "Alarm and Event Analysis for detecting Productivity Bottlenecks," ISA, 1999.

8. "Use Critical Condition Management to Improve Your Bottom Line," ARC Strategies, ARC Advisory Group, April 2002.

9. Donald Campbell Brown & Manus O'Donnell, "Too Much of a Good Thing? Alarm Management Experience in BP Oil, Part I: Generic Problems With DCS Alarm Systems," www.asmconsortium.com.

10. Dick Perry, "Alarm Systems and Their Role in Abnormal Situation Management, Part II of IV," Instrument and Controls, SAIMC, July 2000, www.instrumentation.co.za.

11. C.T. Mattiasson, "The Alarm System From the Operator Perspective," ASM Consortium, www.asmconsortium.com.

12. D. Shook, "Alarm Management White Paper," Matrikon.

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William L. (Bill) Mostia Jr., PE, of Exida, League City, Texas, has more than 25 years experience applying safety, instrumentation, and control systems in process facilities. He may be reached at wmostia@exida.com.