The typical plant control room has changed dramatically over the years. Alarm management – which once was simply a sound or flashing light designed to get the control room operator’s attention – has changed dramatically, too. Many control rooms have replaced analog panel boards with multiple screens of bright and colorful representations of plant equipment.
Programmable logic controllers (PLC) and distributed control systems (DCS), used to automate electrical processes, have allowed engineers to add alarms easily and cheaply, enabling companies to measure and control plant variables in ever-greater detail. But when it comes to alarm management, is it always better to have more? Today’s plant control rooms are in danger of generating so many alarms that they are no longer effective. This is where process improvement practitioners can offer assistance, by completing a 5S effort to organize a plant’s alarm system.
The introduction of mulitple alarms, many of which can be trivial, means operators may spend a significant amount of time acknowledging alarms. This can create a reactive mindset, where operators start to think their job is solely to respond to alarms. Worse still, it can lead to a culture of ignoring alarms, particularly when the number of false alarms rises. Some businesses have lost sight of which alarms are critical and even what purpose these alarms serve. This loss of focus can lead to dangerous consequences. Instead, operators should be proactively monitoring alarm systems. After all, when an alarm sounds, something has already potentially gone wrong.
Once an alarm is in place, engineers, operators and management may be hesitant to remove them, just in case something happens or is missed. Control room culture can be deep rooted and difficult to break. However, for process improvement practitioners, it is worth remembering that investigations into fatal accidents at Texaco (Pembrokeshire, U.K.) in 1994 and BP (Texas City, Texas, USA) in 2005 highlighted that too many alarms and operator overload were contributing factors to the incidents.
Applying 5S to Control Rooms
The Japanese philosophy of 5S – abbreviated from the Japanese words seiri, seito, seiso, seiketsu, shitsuke and often translated to sort, straighten, sweep, standardize and sustain – is a concept many people in manufacturing are familiar with. It’s sometimes referred to as “workplace organization” or “visual management,” and designed to tidy up working areas, increase efficiency and improve safety. The overriding benefit of 5S is that it allows workers to determine at a glance whether something has gone wrong. The following table outlines how process improvement professionals can help use 5S to bring these benefits to the control room.
|Use in the Control Room
|Sort – Separate and categorize the materials and tools needed for the task and remove anything that is not required.
|Use Pareto analysis to identify and highlight main alarm offenders. Identify the different alarm types in the control system. For example, emergency, safety, normal operation, quality and equipment failure. To manage changes, set up a system to introduce new alarms and ensure that alarm overload is not re-introduced.
|Straighten or Set in Order – All materials and tools should be clearly labeled and positioned conveniently close to where they will be used.
|Set alarm priorities. Identify function of alarm(s) and the required or desired operator actions upon alarm. Identify alarms that add value to the consistent safe operation and quality of the plant. Use different alarm sounds to distinguish between alarms. For example, a different sound or volume for priority alarms. Use control screens to program flashing lights or other means of attracting the attention of the operator.
|Sweep or Systematic Clean – All materials and tools should be restored to the correct place after use (or replaced) and the area kept clean.
|Remove problem alarms. Reorganize alarms into groups.
|Standardize – Working practices should be consistent and standardized, and everyone should know their responsibilities.
|Roll out across other plant systems or areas across the facility. Standardize alarm types or groups, responses to alarms, alarm sounds and volumes of alarms, and visual techniques such as flashing lights. Roll out a system for managing change and introducing new alarms.
|Sustain – Standards should be maintained and reviewed to prevent a gradual decline back into old practices. At the same time, new and better ways of working should be continually considered.
|In daily plant meetings, discuss and report on alarms, including main offenders and operator responses. Introduce better operator training as needed.
By using 5S principles, process improvement practitioners can help reorganize and standardize alarm systems and ensure a safe, efficient and effective alarm management process for control rooms.