Can DCS HMI impact operator performance

Many recent accidents have clearly identified the contribution of bad alarm management practices as a major contribution. Action has been taken by regulators, standards bodies and customer forums to provide good guidance on alarm improvement, targets have been set through organizations like EEMUA who have effectively raised the bar in all industrial sectors. However, many struggle still with alarm management, especially alarm floods, and will continue to, until they address their HMI issues.

Little has been published on the contribution of poor HMI design but the significant contribution to major accidents and losses is evident in the accident reports. Common themes being loss of the big picture, data overload, missed information or alarms, operators being reactive and waiting, they are operating by alarms.

The continued use of crowded graphics with no color restrictions producing visual noise is still not on many managers radar. Even though best practices and use of grey-scale graphics have been identified as a major step forward and have demonstrated the ability to improve an operators performance to detect, diagnose and recover from abnormal situations.

A new topic to our industry but not too many others is Situation Awareness and how alarms are just tool to help an operator become aware of change, this topic looks at our past and demonstrates how our operators' HMI used to be less dependent on alarms through the continuous monitoring of plant and process trends and the ability to see the "big picture".

We have the technology today to address these issues, our DCS systems are very capable but are being abused by over use of color and fancy three dimensional graphics that are compromising situation awareness.

We will never resolve alarm management issues until we get the balance right and focus attention on good HMI practices, many now have a written alarm philosophy, how many have a HMI philosophy. To mitigate major accidents and losses we need high performance HMI that truly impacts an operators performance. What we have today does not work and has proven that it exposes us to unacceptable risk.

This was originally posted in "The Process Automation Usability Project." See the responses he got there and contribute with your own here.

Katherine Bonfante is Senior Web Editor for and Email her at or check out her Google+ profile.