The foundation of alarm documentation should be an alarm rationalization where each individual alarm is discussed, defined and prioritized by a team. This team usually consists of one or two experienced operators, a production specialist or engineer, a control specialist or engineer, and, as needed, a maintenance engineer and other specialty engineering personnel. The alarm champion's role is to participate in alarm rationalization and educate team members on the guiding alarm philosophy.
An important component of alarm rationalization is identifying causes, consequences and corrective actions for alarms. To be valuable, these must be documented in the AKB and operators must have easy access to this electronic documentation. The alarm champion is responsible for ensuring that the documentation is up-to-date and prospective changes follow MOC procedure. The alarm champion also must ensure that the current DCS alarm configuration is regularly audited to verify alarm settings match the current AKB.
An important and sometimes underestimated responsibility of alarm rationalization and of the alarm champion is proper alarm configuration. This involves defining process conditions that should trigger an alarm and consequently setting the alarm limit or set point, any delay and dead band to avoid alarm chattering. Actual implementation should be the responsibility of control systems personnel.
Another potential important duty for an alarm champion is participating in process hazard analysis (PHA), process change analysis (PCA), safety integrity levels (SIL) and other investigations to ensure new and existing alarms are properly evaluated and rationalized.
Overseeing the continuous improvement process of alarm management is the responsibility of the alarm champion. This involves very rigorous data mining and analysis, identifying and addressing problems, and following up to confirm resolution of issues.
To facilitate the monitoring of alarms, we have defined the three KPIs and associated goals for alarm management (based on EEMUA 191 and SP18 recommendations):
• Average number of alarms per hour per operator shouldn't exceed six;
• Average number of standing alarms (those active for more than 24 hours) shouldn't exceed nine; and
• Peak alarm rate per operator (defined as maximum number of alarms during any 10-minute period within a month) shouldn't exceed 10.
These KPIs are monitored 24/7 and automatically calculated.
In addition, automated standard reports and drill-downs should be established to assist the alarm champion in continuous review and analysis of alarm data for patterns and inconsistencies to focus efforts on problem areas. Upset conditions and alarm floods should receive particular attention. During those periods a wealth of information is created that should be used to improve the performance of the alarm management system. The importance of providing easy and automated drill-down cannot be overstated. Expert alarm champions use this opportunity to identify causes of alarm floods and nuisance alarms to correct these issues.
In addition, expert alarm champions should explore options for real-time alarm management provided by their specific automation environment. Many modern control systems provide capabilities such as state-based alarming, in which alarms and their set points are configured for different operating conditions (start-up, shutdown, product switches and normal operation), suppression of alarm floods by conditional alarming, or shelving of alarms because of broken sensors (see: "Consider State-Based Control", and "Adroitly Manage Alarms"). This can go as far as shelving, subsuming and predicting alarms based on real-time data and even creating new rules based on alarm data or on information stored in the causes, consequences and corrective actions of the AKB.
Adoption and implementation of these advanced applications require the alarm champion to engage in additional activities:
• Support the advanced alarm management application, specifically act as interface to operators;
• Monitor a new KPI for the reduction of alarms;
• Check for newly identified alarm patterns or predictions;
• Validate and get approval to implement (via MOC) new alarm rules and predictions;
• Activate approved alarm rules and predictions; and
• Ensure no independent protection layer alarms are being shelved or subsumed.
These are areas where an expert alarm champion can excel and make a significant difference by producing a step change in alarm management performance. Ultimately, this helps board operators effectively manage critical upsets and avoid serious incidents.
The work of alarm champions has already proven to be beneficial at LyondellBasell early adopter sites. At one of the company's Rotterdam units alarm loading and peak alarm rates have dropped by more than a factor of two. At one of its Houston units the average alarm loading has decreased by a factor of four, while at two other Houston units the number of standing alarms has halved.
The company fosters experience exchange through a specifically created Critical Condition Management user group. In addition, we use a center of excellence to provide training and ensure consistency.
LyondellBasell has learned what is required to become an effective alarm champion. The person must understand and buy into the alarm philosophy and sometimes challenge operators or engineers as needed. Good communication and leadership skills are essential for building positive relationships with operators and maintenance staff. Of course, support by local plant management is key to alarm champion success.
LOTHAR LANG, Ph. D., is a consulting engineer for Lyondell, a LyondellBasell company. E-mail him at Lothar.Lang@lyondellbasell.com.