What is alarm management?
In a process plant environment controlled by an operator using a control system like a DCS or a Programmable Logic Controller (PLC), alarm management is required. The alarm is a signal given to the operators or workers when the process value deviates from the normal operating conditions.
In case of abnormal situations in a system controlled by PLC or DCS, the controllers call for human intervention through the alarm. The main objective of alarm management is to avoid or reduce physical and economic losses by operator action in response to the alarming situation.
Alarm management refers to the processes and practices for determining, documenting, designing, monitoring, and maintaining alarm messages from process automation and safety systems.
The advanced alarm management system is a mix of technologies that help make productive alarm systems in line with industry guidelines and standards such as Engineering Equipment & Materials Users Association (EEMUA) 191, International Automation Society (ISA)-18.2, and Abnormal Situation Management (ASM) standards.
Generally, there are two types of alarms: Fault alarm and Event alarm. The event alarm indicates a transient state during the operation of the equipment. A fault alarm occurs during an abnormal situation or expected.
Alarm management system:
A general alarm management system is shown in the picture below:
For measuring various plant parameters such as temperature and pressure, sensors such as resistance temperature detectors (RTDs), bellows, pressure detectors, etc. are used. The sensor output signal is electronically processed and sent to various circuits serving as controls, displays, and alarms.
Each alarm circuit for a parameter has a setpoint and actuates the alarm display. Plant operators in the control room decide the nature of action should take according plant status. These adjustments would affect plant processes and the results would be detected by the sensors and transmitted back to the alarm displays of HMI
Advanced Alarm management system:
Advanced alarm system reduces inefficient alarms thus reducing the losses caused by ineffective alarming. Reducing the number of alarms needed by operators increases the operator’s performance.
Like the conventional alarm system, the factory, the detectors, and the signal processing circuitry are identical. Typically, the advanced alarm system requires more information processing capabilities. Usually, the outputs of the advanced alarm system are input to some integrated HMI that can use visual displays or other display tools to provide operators with alarm data.
The operators would use their protocols and the HMI to evaluate the situation, prepare responses and take whatever action is necessary to control the facility.
Advantages of Advanced alarm management system:
- Improves operator effectiveness, protecting plant uptime and safety, and reducing losses.
- Reduces time and effort to develop, deploy, and maintain alarm systems
- Identifies alarm system problems and performance, as well as operator workload
- Untimely response to an alarm due to poor prioritization
- No show of the alarm due to inhibited or disabled alarms
- Avoid flood of alarms and missing events due to poor configuration
