Abstract: This metric is the ratio of the maintenance personnel who are actively doing the maintenance work (direct) to the maintenance personnel supporting the maintenance work (indirect). Direct personnel include those workers in the maintenance department that repair, maintain, modify or calibrate equipment.
MIDI (Musical Instrument Digital Interface) is a protocol designed for recording and playing back music on digital synthesizers that is supported by many makes of personal computer sound cards. Originally intended to control one keyboard from another, it was quickly adopted for the personal computer.
Improvisation means playing notes that are not written out for you. You can do that on many levels, and it has been done in many contexts. In baroque music only the left hand of the keyboard accompaniment was written out, with numbers indicating the harmony structure. The right hand was made up by the player. You could call this improvisation.