Reliability & Maintenance

Process management: Raise an alarm about alarms

Sure, having more alarms is a plus if they contribute to better plant operation.  But nowadays, more and more plants have numerous alarms that are causing more trouble than they are worth.

By Mark Rosenzweig, Editor-in-Chief

If you are like me, the twice-a-year ritual of moving clocks ahead and then back for daylight-saving time has gotten a lot more complicated in the last few years. Electronics are to blame. Just about every device nowadays seems to come with a digital clock, whether or not the clock serves any useful purpose. How many of us really need a toothbrush that also tells time? There probably are at least 20 gadgets around my house that require resetting.

Worse yet, many designers of such electronic products seem to be so taken by what the sophisticated circuitry allows them to do that they forget about ease of use. It is frustrating to have to fish out the operating manual every six months to remind myself how to change the time on the television. The process is nonintuitive, to put it mildly. I curse the idiot who decided that my videocassette recorder shouldn’t have any built-in buttons to adjust the clock. The product’s designer decided that oddly named multipurpose keys on the remote control made more sense.

Instead of simply and quickly turning a knob to move an analog clock’s hands, we wind up wasting time to set the time. This strikes me as a classic case in which electronics have made simple tasks harder.

However, before you call me a Luddite, let me quickly add that I realize that advances in electronics have had an overwhelmingly positive impact, both on individuals and chemical industry operations.

Our industry certainly benefits from electronics, however, there’s a downside. Process control systems provide a perfect example. Today’s systems allow more responsive and accurate control than previously possible. We can take advantage of sophisticated control algorithms and data-analysis capabilities, self-diagnostics on equipment and sensors, and faster and more reliable means of transporting information. However, electronics also have led to alarm overload, which compromises plant operation.

As Ian Nimmo explains in his article on page TK, in the old days of panel boards in control rooms, restrictions in physical space limited the number of alarms to a few critical ones. Today, though, space isn’t a barrier, and adding alarms to control systems involves minimal, if any, cost. Whereas a plant might have had 150 alarms in the panel-board days, it now may boast 14,000!

Sure, having more alarms is a plus if they contribute to better plant operation. The problem is that many alarms are more trouble than they are worth. Lots of sites suffer from a multitude of nuisance alarms. At one plant, Nimmo says, more than 3,000 such alarms occurred daily, on two days in a two-week period. Four other days each had more than 1,500 nuisance activations. He adds that the “top 10” bad actors often account for a large share of these.
This activation excess impacts operations. Nuisance alarms not only needlessly distract operators but they also can bury important alarms in the cascade of activations, and even desensitize operators to meaningful alarms.

Many chemical companies certainly appreciate the problem. However, that doesn’t mean they are adequately addressing it. As Nimmo stresses, there is no quick fix resolving alarm issues requires a well-thought-out, adequately funded and carefully managed program. However, firms that do the job right are achieving tangible results in improved day-to-day operations, fewer incidents and operators are better able to handle real alarms.

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