Mode

I am aware of no useful definition of “mode” that is universally¹ accepted in System Engineering.

I have, however, used “mode” to indicate a group of functions, none of which are disabled by some supervisor or executive². That is, within a single “functional mode”, any given function of that mode can execute according to whatever transition rules are in effect without something (or somebody) having to turn things on or off.

Contrast with state. See also states and modes.

Footnotes

1.   Or even generally.[↩]
2.   Which might, or might not, also be a function of the system in question.[↩]