Chemical Processing - February 2008 - (Page 34)

Hope exists If your plant is struggling with huge numbers of alarms, take heart. Consider the total number of alarms that exist on an automobile. Although cars are complicated systems involving many different components, electrical circuits, frequent load changes and even critical safety operations, only a few alarms usually appear on most automobiles: e.g., low fuel level, unfastened seat belt, unauthorized entry, and engine maintenance needed. Each of these alarms represents an abnormal situation requiring a user response and presents information in a format that’s timely, accurate and easy to understand. A single alarm (not multiple alarms) warns of each type of abnormal situation. This isn’t to say that a manufacturing plant should have very few configured alarms — but it does suggest that adherence to alarm management best practices can result in far fewer alarms than would otherwise exist. Indeed, it’s common for alarm remediation projects in industry to reduce total alarms by over 70%. Take the crucial steps The key considerations in achieving effective alarm systems include defining objectives early in a project’s life (i.e., in a MONITOR VISCOSITY SIMPLY Sense Motor Horsepower with Universal Power Cell EASY INSTALLATION • No holes in tanks or pipes • Away from sensitive processes VERSATILE • One size adjusts for motors, from small up to 150 HP • Works on 3 phase, fixed or variable frequency, DC and single phase power SENSITIVE • 10 times more sensitive than just sensing amps CONVENIENT OUTPUTS • For meters, controllers, computers 4-20 milliamps, 0-10 volts CALL NOW FOR YOUR FREE 30-DAY TRIAL 888-600-3247 WWW.LOADCONTROLS.COM 34 • February 2008 plant’s alarm philosophy or a system’s functional requirements), adhering to the definition of an alarm, and implementing alarm-management best practices. The following checklist can help plant project teams in avoiding some of the pitfalls in designing and implementing alarm management systems and in working more effectively with vendors. • Identify desired alarm functionality when defining alarm management philosophy and system functional requirements — near the beginning of a project when there’s still time for customization (e.g., outputting alarm alerts to pagers). Don’t assume that vendor off-the-shelf products will provide all desired alarm functionality. • Define in the early stage of a project what use will be made of alarm records. This can influence the determination of alarm attributes (e.g., categories and priorities) when designing/rationalizing individual alarms. It also can help identify the need for specific data mining and reporting software utilities. • With minimal exceptions, configure alarms only for abnormal situations requiring a response. System permitting, use other areas of the HMI for informational/notification messages or use color and other graphical means to distinguish between alarms and such messages. • When designing or rationalizing alarms determine and document expected operator response. Consider coding the expected response on-line. Remember that an alarm’s purpose is to alert, inform and guide. • Include tools in historians (or third-party products such as alarm loggers) to allow for the querying, sorting, charting and batch reporting of alarm records. For example, a Pareto chart could be used to depict individual alarm frequency, thereby helping engineers identify and focus on the situations generating the most alarms. • Implement a monitoring program and pursue continuous improvement (including reduction of nuisance alarms). • Maintain the mindset that nuisance alarms can be a major frustration for operators, may contribute to their missing real abnormal situations, and, if excessive, may call into question the qualification/validation of the system. • Recognize that responsibility for alarm management typically is shared among process engineers (who should specify what alarms are required), automation engineers (who should implement the requested alarms) and operators (who are the primary customers). Assigning alarm management responsibility to only one or two of the above groups often is a formula for failure. • Become familiar with ISA’s S-88 standard [4] (for batch processes). • Keep on eye out for ISA’s S-18 Standard on “Management of Alarm Systems for the Process Industries.” It likely will be published later this year. This standard builds upon the best guidance available in www.chemicalprocessing.com http://WWW.LOADCONTROLS.COM http://www.chemicalprocessing.com

Table of Contents Feed for the Digital Edition of Chemical Processing - February 2008

Chemical Processing - February 2008 Contents From the Editor ChemicalProcessing.com Field Notes In Process Energy Saver Compliance Advisor Nanoparticle Safety Raises Questions Take the Pressure Off Vacuum Systems Achieve Optimum Centrifugal Pump Performance Rethink Batch-Manufacturing Alarm Systems Dr. Gooddata Orlando Plant Pioneers HMI Migration Strategy Process Puzzler Plant InSites Equipment & Services Ad Index Product Spotlight/Classifieds End Point

Chemical Processing - February 2008

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