Stephen Reilly, ProSys
If a picture is worth a thousand words, then there is plenty for your DCS operators to talk about. When they have a clear human machine interface (HMI) presenting their process to them, your company can expect more money in its pockets as a result. Recently, my fellow ProSys engineer, Dr. James Henry, emphasized this importance of the operator interface layout in enhancing the operators’ ability to control the plant processes at the ISA Process Control and Safety Symposium in Houston, TX.
Citing David Meister’s Human Factors: Theory and Practice, James stated that control system design must be addressed by management because “a major cause of (human) error is built in to the system during its development by inappropriate design practices.” He then demonstrated the use of faceplates, a standard HMI component on most DCS’s, as an example and compared it to direct entry operation, the standard method applied in ProSys’ IDv3 graphics package. With the former method inherently requiring more steps than the latter, more potential for operator errors arise, leading to higher operational risks and expected costs. Thus, some easy financial savings are made when switching to a direct entry method.
A system re-design can also make money proactively using some particularly helpful displays such as emergency shutdown diagrams (ESD), permissive logic, and overview variances. These intuitively-designed graphics can quickly alert operators to hindrances in start-up/shutdown periods, reducing many hours of downtime, and they can also keep operators focused on operational targets during normal operation.
If you would like to see how ProSys could improve your HMI graphics, contact us soon!