A human factors improvement on supervisory alarms in wastewater treatment system

The automation of the computer monitoring system has already been extensively used by industries. This study introduces a high-level automation water treatment system that was developed in a semiconductor plant. The original system was so designed that it could monitor the system in a very sensitive way and display and records all the alarms in detail. The system was considered of convenience and security because of such features. However, the design of supervisory alarms in the system failed in considering the human factors. The problem was identified and improved by applying human factors into the system. NASA-TLX evaluation on performing the monitoring tasks was carried out with a group of technicians/engineers before and after the improvement. The subjective and objective indexes indicated that the improved human factors alarm design performed better. The subjects´ satisfaction was very high with the improved system. The mental workload of the subjects was reduced and the performance improved remarkably. It is concluded that detailed information may not be a good idea for monitoring system. Less detail but fit the needs of the task is a better way for such a system design. The result is applicable to not only semiconductor industry but also to other industries.