Alarm management: A pillar of process safety management
The following describes how an adequate implementation of alarm management is a fundamental part in process safety management (PSM).
The following describes how an adequate implementation of alarm management is a fundamental part in process safety management (PSM). Since alarm management is one of the best strategies for diagnosing, evaluating, improving and controlling the performance of the various processes involved in the hydrocarbon processing industry, this strategy enables personnel to structure and facilitate the understanding and involvement of staff with the main elements of PSM.
In addition, this article details how concepts, stages, indicators, etc., of alarm management are compatible with the main elements of PSM, allowing it to be incorporated into this management system.
One of the main challenges for a sustained and successful implementation of PSM is that it remains updated over time and provides timely and correct information about a process’ performance, so that its elements allow it to manage the current deviations. This challenge is addressed by the implementation of an adequate and crucial alarm management.
To implement proper alarm management, the following stages should be considered (FIG. 1): Diagnostics (from the initial state of the alarm system), analysis (identification of deviations and their sources), implementation (application of improvement actions) and operation (for control and monitoring of the final state).
FIG. 1. Stages of development of alarm management.
Developing alarm management
During the development of alarm management, the operational discipline that an organization has developed over time is assessed. During this development, fundamental documents are reviewed that are sometimes not adequately updated or, at least, with the necessary detail or frequency, identify whether control strategies are aligned with current process requirements for safety and productivity, and, above all, identify whether there are properly documented and supported changes or adaptations under the organization’s policies and standards. In addition, this is an excellent opportunity to bring together teams from different areas of an organization (e.g., operations, engineering, security and maintenance) to improve operational and safety standards, strengthening teamwork.
Diagnostics
This is the base stage of any alarm management implementation process. Before starting the process, it is advisable to evaluate the following symptoms:
- Control screens are covered by active alarm signals, even under normal operating conditions
- There are active alarms for long periods of time without being attended by the staff in charge
- Massive alarm recognition without analysis or prior investigation (i.e., clean alarms)
- Deactivation of alarms, decrease of the volume of the audible alarm system or modification of alarm values in the system.
If these symptoms occur in a system, it is likely that an alarm management system should be implemented to strengthen the process management system before an unexpected event occurs.
To have an adequate starting point, it is advisable to begin with the review of the philosophy or strategy of control, alarms and automatic interlocks—to have a good understanding of the processes involved and, above all, the level of updating and changes made over time. Typical documents to review at this stage are the control philosophy, facility and process design, operating procedures and cause and effect matrix.
After the process is understood and reviewed, the metrics for the definition of the level of acceptability are established, which will be the main criterion for the measurement and subsequent control of the alarm management to be implemented. Many ways exist to establish this criteria; however, having a reference based on recognized standards or good practices will provide greater support and a future possibility of reference with other similar processes or plants.
As an appropriate and well-accepted criterion in the industry, the Engineering Equipment and Materials Users Association (EEMUA) 191 standard1 can be adopted, which sets the level of acceptability depending on the number of alarms recorded under normal conditions (TABLE 1).
Depending on the level of acceptability determined during the diagnosis, the goal is to improve the level as implementation progresses, recommending the “manageable level” to be achieved (i.e., one alarm every 5 min).
Control systems usually have functionalities that allow the alarm records to be obtained, which, in turn, are properly organized according to the process variables (flow, pressure, temperature, etc.) to which specific process or equipment are associated, to which signal or controller they belong, and even the type and level of alarms or automatic stop (FIG. 2). This makes it easier to manage the information for the analysis stage, allowing personnel to export that information to computer tools such as spreadsheets or databases. To avoid distortions or inaccurate decisions, it is important to consider the following when selecting evaluation periods:
FIG. 2. Getting data considerations.
- Information should be taken during periods when the process has developed within normal operation (i.e., without scheduled or unscheduled plant shutdowns)
- Preferably under relevant operating conditions (i.e., processing loads or relevant production levels).
An important part of the diagnosis is the validation of staff competencies that carry out the process control (e.g., operators, panelists and supervisors) to identify the training needs and action plans. Experience indicates that the fundamental documents previously listed are often set aside, so they must be incorporated with the most up-to-date versions for new personnel training.
Analysis
This stage is based on the information obtained in the diagnostics stage. Several types of deviations can be found in this stage, which depends on the particularities of each case (process type, management style, organizational culture, etc.). However, at this stage, it is advisable to group the variances into the following aspects:
- Rationalization. It is important to be clear that rationalization is not an alarm removal process but a process of managing alarms in the right place at the right time. Depending on the configuration of the control systems, there are processes that are controlled in a certain place and monitored in the main control room. For example, a truck loading station usually has a special control workstation—different from the main control room—that is only monitored. However, redundancy is usually incurred when setting alarms, causing them to appear on both stations. This condition can lead to a lack of operational discipline, since being at both stations, the operators can expect the other to attend to them and vice versa, or worse, the alarm is not attended after a long period of time. For this type of case, it is advisable to establish a level of criticality of alarms that should go in redundancy towards the main control room, given its level of impact on the process and its security or its interrelationship with the other processes of an installation (processing, storage, etc.).
Other types of rationalization examples can be found in the alerts of the same system (warning of upcoming maintenance, capacity alerts, etc.), which are usually seen as alarms and distract the attention of operations staff. Usually, the architectures of the control systems have maintenance or support modules managed by the maintenance or instrumentation personnel. These types of alarms can be managed through these modules only, allowing them to clear the control screens of the process itself.
- Review of inconsistencies and failures. It is important to identify the nature of the alarms that are presented on a recurring basis during normal operating conditions. The main causes to be analyzed include:
- Changes in process capabilities (processing load increases, changes in operating conditions, different modes of operation, etc.)
- Inadequate calibration of equipment or instruments
- Uncontrolled changes in alarm settings in the control system
- Errors in the process design.
This review requires a detailed analysis in the engineering and design of the equipment, especially in the instruments and equipment associated with the recurrence of alarms. For example, it is common for an automatic cutting or emergency valve to set an opening or closing time. In case this time is extended from a defined value, an alarm will be triggered indicating a problem during operation. However, since the valves complete their stroke, there is a phenomenon of normalization of this deviation since the operator trusts that the valve will open or close completely and the alarm will be recognized without further action or analysis. This can be risky in the case of a real occurrence. In this situation, it is advisable to check or calibrate the drive time of the valves and inspect for any internal damage to the valve or actuator to eliminate the recurrence of such alarms.
Another example is when uncontrolled changes are made to alarm values by operational personnel to use alarms as an alert mechanism when reaching a desired value, distorting the functionality of alarms and adopting them as a means of control. This constitutes a deviation from the operational discipline that must be promptly attenuated.
- Adequacy to the process. Based on the information reviewed at the diagnostics stage, this aspect requires a detailed analysis of the process and the changes that have been made to it. For example, when plant capacity expansions are carried out, it leads to flow increases in certain process streams, implying that the configuration of the instruments must also be modified (rangeability), along with the new alarm values according to the new flows to be handled. Without these changes, recurring alarms are often presented and the phenomenon of normalization of deviation from operational personnel occurs.
After completing the analysis and identifying the causes of the recurrence of alarms, it is necessary to review the operating procedures that allow the proper management of the alarms, which establish the necessary permissions to make changes. In this regard, training opportunities for operational staff should be identified, as well.
- Implementation. Since changes to the alarm system will be made in this stage and the proper management of change (MoC) must be applied, this stage should only begin after the organization has validated and approved the final reports of the previous stages.
Alarm management implementation should be aligned with the safety policies of the organization, especially with the elements of PSM, so that its implementation will be integral and effective to establish an operational discipline in the staff and achieve a link to the operational philosophy with the safety culture of the organization. This is the critical moment that organizations face to succeed in this implementation.
Identifying the elements of PSM
According to the elements established for PSM1, during alarm management implementation stages, specific elements are developed that facilitate the development of process management or complement the existing ones.
To identify and interrelate the stages of the development of alarm management with the main elements of PSM, TABLE 2 proposes a conceptual guide scheme. The scheme in TABLE 2 shows that the implementation of alarm management covers all elements of PSM, making it easier for the organization to implement it, upgrading the organization’s operational and safety standards.
From diagnosis as a baseline and then analysis, implementation and sustainable operation, several elements develop during stages of implementation. Other elements are developed as their need is determined and incorporated or improved.
For example, the revision of the control philosophy during the diagnostics stage serves as the basis for the analysis of the process and validates the strategy or philosophy of alarms, as well as for the review and elaboration of better staff training plans and position profiles for the incorporation of new talents. Finally, this document must be updated each time a change is made, which must be properly managed and be part of the continuous improvement of the organization.
Another example is how the criteria for incident investigation are established or determined. This is one of the most important elements of PSM and where alarm management takes a very important role. Success of its management constitutes a source of predictive information to analyze deviations in operational discipline, equipment reliability and staff competence, among others. In addition, during the diagnostic and analysis stages, it can be determined whether it is necessary to implement a certain research methodology according to the new requirements of the process and policies of the organization.
Establishing management indicators
Two large groups of management indicators exist: lagging and leading. This analysis will focus on the latter since it is more aligned to the objective of PSM, which is to ensure the reliability of anticipating failures in processes based on the continuous analysis of deviations and on a solid management of information.
TABLE 3 details a list of indicators related to alarm management that can be incorporated into PSM dashboards in organizations that have implemented it. It is important to note that these indicators—all related to alarm management—are geared with the elements of PSM and could facilitate performance measurement and be integrated into the organization’s PSM scheme.
General recommendations
The following are general recommendations to establishing alarm management:
- Consider the implementation of alarm management as a pillar for strengthening or consolidating PSM, involving the resources needed to achieve the desired results.
- The alarm management makes PSM assurance easier due to its aspects being linked to PSM elements.
- Consider a project approach to its implementation, especially for organizations that have a PMO and can establish management under project management guidelines. This action will speed up and facilitate its implementation.
- Put a lot of emphasis on validations or approvals during deployment. It is advisable to apply an appropriate transition plan to avoid uncoordinated actions during the implementation of a certain stage. HP
LITERATURE CITED
- Center for Chemical Process Safety, Guidelines for Implementing Process Safety Management, 2nd Ed., Wiley-AiChE, July 2016
The Author
Moreno, C. G. - QHSE Institute, Lima, Peru
Carlos García Moreno is a Senior Consultant with more than 18 yr of experience in the oil and gas industry. He started his career as a Production Supervisor in an NGL fractionation plant with Pluspetrol Peru Co. Recently, he developed his career in marine terminals with Oiltanking Peru S.A. and Solgas S.A. He earned a BS degree in petrochemical engineering from the National University of Engineering (Peru), an MBA from Centrum Católica Business School and an MS degree in project management from ESAN Business School.
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