In a system with many options, most are not visible on screen. On initial operation, users are not aware of most of the hidden options. Occasionally, though, some of the parameter values change, affecting system behavior. When the change is critical, users must identify the parameter that affected the system behavior and change it back to its original value.
Practically, the parameter that may have changed is unknown to the users, and they need to examine all the relevant options in order to decide which parameter is responsible for the undesired system behavior. The users must be trained to know the effects on all parameters in all possible situations, in order to ensure fast recovery from such situations.
Updated on 28 Feb 2016.