YOKOGAWA has completed the development of AAASuite, a comprehensive alarm management system that optimises and enhances process alarms issued by control systems.
AAASuite improves operator performance by providing timely notification of only necessary alarms, thereby preventing alarm flooding and enabling safe, stable, and cost effective plant operations.
Recently, industrial plants have been aggressively streamlining their control rooms and control systems, reducing the number of operators to achieve more efficient operations and improve their prospects for survival in the midst of prolonged recession and harsh global competition.
Process alarms are incorporated in control systems as an essential monitoring function that ensures the safe and stable operation of plants. Ideally, alarms should be systematically and uniformly distributed at the transition points between normal, upset, and shutdown plant statuses so that operators are notified in a timely manner and only when necessary.
In conventional non-streamlined control rooms, operations were dependent on having an abundance of personnel, including some with special expertise, producing a situation in which alarms tended to occur randomly.
If such control rooms and control systems are realigned without undergoing proper corrective measures, even a minor variation in process status can immediately trigger numerous alarms.
As a consequence, operators may miss critical alarms and fail to quickly or correctly respond to abnormal situations, resulting in operations that exceed product design specifications, the loss of raw materials, delayed deliveries, damaged equipment, plant shutdowns, or even disaster.
In the worst-case scenario, a manufacturer can incur losses far exceeding any economic benefit that could come from the streamlining of a control room.
This is why alarm management, which includes the optimisation and upgrading of alarms, has become a priority for many plants.
Some have introduced alarm analysis and reporting systems from various suppliers in order to get a better handle on their plant operations.
However, because of employee turnover and/or reduction in budgets, many of these plants do not have a sufficient number of engineers on hand who possess the level of plant experience and knowledge necessary to be able to take full advantage of these analytical systems.
Consequently, many of these plants have not yet succeeded in fully solving the problems that they had sought to address with the introduction of these systems and are still plagued by alarm flooding.
AAASuite features include:
* Nuisance alarm detection and diagnosis. AAASuite automatically detects typical nuisance alarms and notifies both the alarm causes and the required corrective measures to operators. Typical nuisance alarms such as repeating HI/LO alarms caused by improper alarm settings and chattering HI/LO alarms caused by improper PID parameter settings can be detected.
* Dynamic alarm setting (Option). AAASuite stores the optimal alarm settings and automatically downloads the required settings to the control system when a plant startup, plant shutdown, product grade changeover, or process load change occurs. Furthermore, when operators are allowed to change alarm settings during plant operation, the new settings will be automatically uploaded to the AAASuite database the next time there is a change in the operating conditions.
* Nuisance alarm suppression. AAASuite automatically prevents the repetition of nuisance alarms that are detected through the aforementioned detection and diagnosis function, utilizing the control system's functions. When the process status changes in such a way that unnecessary alarms no longer occur, AAASuite automatically lifts this alarm suppression.
* Alarm enhancement. AAASuite automatically generates more value-added alarms including the periodic re-notification of longstanding HI/LO alarms caused by unstable plant situations and the predictive alert of critical HH/LL alarms that can trigger an interlock sequence.
Alarm Management System