4.3.2 Reversionary mode
The INS should allow simple and effective operator action to override or by-pass any automated functions. The INS should resume automatic functions only after an appropriate message and intended operator action, considering all necessary starting conditions.
4.3.3 Alarm management
4.3.3.1 An alarm management system should be provided.
4.3.3.2 The INS alarm management system, as a minimum should comply with the requirements of the Organization.*
4.3.3.3 The number of alarms should be kept as low as possible by providing indications for information of lower importance.
4.3.3.4 Alarms should be displayed so that the alarm reason and the resulting functional restrictions can be easily understood. Indications should be self-explanatory.
5 Ergonomic criteria
5.1 Cognitive ergonomics
5.1.1 Integrated display and control functions should adopt a consistent human machine interface (HMI) philosophy and implementation.
5.1.2 The HMI should be so designed that the provided information is clearly understood using a consistent presentation style.
5.1.3 The HMI should be so designed that the requested manual inputs can be easily executed.
5.1.4 For manual inputs that may cause unintended results, the INS should request confirmation before acceptance, thus providing a plausibility check.
5.2 Physical ergonomics
5.2.1 Controls and displays
Particular consideration should be given to：
- symbols
- controls, and
- layout.
* IMO resolution A.830(19)
