This figure demonstrates key topics in error protection. It shows the need to shift the operator's role from a controller to a supervisor, by tackling typical design problems, in automation and in information presentation.

Control design

  Manual control of boiler temperature is attention consuming and error-prone. According to the Human Factors variant of Murphy's Law, operators might fail to do it reliably.

  To mitigate these risks, the control should be automated:

• The operator and the On-Off switch should be replaced by an automated process controller, namely, a thermostat.
• The operation indication should be replaced by a thermometer.

Information presentation

  A typical barrier to problem solving is the absence of information about the problem and its sources ( reference ...).

The design should include special means to ensure that the operators have all the information required for understanding the situation and for recovery, and that the information is presented in a way that ensures fast and reliable perception.

• The LED display showing the boiler is On may be replaced by a thermometer, showing the exact temperature, and a three-state LED display, highlighting risky situation
•  An alarm may be added to notify the operator about overheating.

Updated on 08 Feb 2017.