This chart presents a simple 2-state machine, with elementary control, using  a solid On-Off push button. It exemplifies the problem of human-machine compatibility, in case of fault of machine or the control, demonstrating the following resilience issues:

• The need for feedback about the operational situation
• The need for information about faults in the control stations
• The rules defining human-machine cooperation.

To enable detection of human-machine mismatch, the system should be provided with add-ons:

• Sensors of the machine state and the operational mode
• Rules about normal relationships between the operational mode and the machine stated: [On, Go] and [Off, Idle]

To facilitate the operator's awareness of the operational situation, the system should be equipped with indicators about the machine state and the operational mode.

To enable the the operator's recognition of the operational situation, the machine should be equipped with indicators of its state, such as by LEDs.

Updated on 20 Jul 2016.