Cognitive ergonomics suggests the brain can only process between 6 – 8 things at any given time1. Yet many system operators are expected to deal effectively with hundreds, if not thousands of alarms at any given time and still do their job without error.
Vastly over alarmed systems are unfortunately more common place than you would think and the results can be catastrophic. Poorly performing alarm systems have been cited as a specific contributing factor in major accidents and losses, and contribute heavily to loss of productivity and inefficiencies. In both the Milton Haven disaster in 1994 and Piper Alpha disaster in 1998 poor alarm design was considered to be a major contributing factor 2.
It is well cited that "alarm storms" or over alarming systems can result in operator error. Historically operators have been blamed for making poor decisions, however the real issue is that operators are not being given the tools to understand potentially hazardous situations in enough time, let alone prevent them from occurring. The more alarms in a system the more confusion and stress the operator is under and there is an increased likelihood of errors.
So why has it got so bad? Here are the top 10 most common problems with alarm handling that reach across all industries:
Top 10 Common Issues with Alarm Handling
1. Many alarm systems have been implemented without any proper guidance
2. Many alarm systems either alarm everything or rely on default alarms
3. There is often little visibility or reporting on how many alarms your operators are having to deal with
4. 80% of alarms are not critical and should not be classed as alarms)
4. 80% of alarms are not critical and should not be classed as alarms)
5. Alarm Quality– Nuisance Alarms (appear regularly and require no action), chattering alarms (comes in and out of alarm states regularly), which all cause distraction
6. Companies are not aligning their alarm practices with recommended UK guidelines (EEMUA 191)
7. Alarm flooding - too many alarms make it difficult to distinguish which need immediate action
8. Too many levels of alarms make it hard to prioritise
9. There is a tendency to think alarming is only important in more dangerous industries such as Oil and Gas when actually all industries can be affected by poor alarm management
10. There is not always one person responsible for Alarm Management
Next week: Taking steps to combat alarm issues
2 High Performance HMI Handbook by Bill Hollifield, Dana Oliver, Ian Nimmo & Eddie Habibi
No comments:
Post a Comment