Audit. To maintain the integrity of the alarm system periodically conduct an audit focused on plant alarm-management processes. A system audit compares operation and performance against the principles and benchmarks documented in the alarm philosophy. The goal is to identify improvements to the system and workflow process, as well as potential modifications to the alarm philosophy document.
What it means. Audits are important for both new and existing systems. For an existing system an audit or benchmark against a set of documented practices (such as the ISA-18.2 standard) may be the logical first step in an improvement project.
Table 3 summarizes the stages and their activities.
A Vital New Resource
The ISA standard provides definitions, practices, requirements and recommendations that will bolster your plant's quest for operational excellence. Like other standards, ISA-18.2 tells you "what" needs to be done but doesn't dictate "how" to do it.
Key takeaways from the standard are:
• Realize that alarm management is an ongoing cyclical process that's never complete. The standard follows a lifecycle approach.
• Develop an alarm philosophy document that tells how your plant will address all lifecycle phases. It should contain everything from the criteria for setting alarm priority, to the colors in HMI displays, to who can make changes to configuration.
• Rationalize alarms to ensure that every alarm has an essential purpose and requires an operator response.
• Create and maintain a master alarm database to document the what, why and how of each alarm. Update this database when changes occur and make this valuable information available to operators.
• Analyze and benchmark system performance. Tools can help you analyze alarm history and can automatically generate a report showing how you compare to recommended key performance indicators.
ANSI/ISA-18.02-2009 requires these activities; they are expected to become standard practice in the process industries.
Nicholas P. Sands is a process control engineer for Dupont in Wilmington, Del., and serves as co-chair of the ISA Alarm Management Standard Committee. E-mail him at Nicholas.p.sands@USA.dupont.com. Todd Stauffer is business development manager at exida, Sellersville, Pa., and also is a member of that ISA committee. E-mail him at email@example.com.
1. "Management of Alarm Systems for the Process Industries," ANSI/ISA ISA18.00.02-2009, ISA, Research Triangle Park, N.C. (2009). 2. O'Brien, L., "Alarm Management Strategies," ARC, Dedham, Mass. (Nov. 2004). 3. "Alarm Systems —A Guide to Design, Management and Procurement," 2nd ed., Engineering Equipment & Materials Users' Assn., London, U.K. (2007).