because it is
Maintenance Professionals are needed to carry out appropriate routine and non routine maintenance safely so that hardware and software are kept in good condition and up to date.
non routine maintenance may be needed if you see your system is running slow like a virus scan or if you can tell if something is wrong, then defrag. Non routine maintenance isn't scheduled unline routined maintenance which is done on a regular basis
There is very little in the way of routine maintenance an office worker can do for the mouse used for computers. One thing that can be done if the mouse is battery operated is to change the batteries when needed. A mouse might also need to be cleaned to become free of germs if there are multiple users of the device.
Two examples of routine maintenance that should be carried out on your computer
Refer to the manufacturer's recommendations for the suggested maintenance schedule. The frequency of maintenance will depend on the size of your lawn and how often you mow. To keep the mower in optimum shape and to get the maximum life from it, consider annual maintenance in the fall or early spring, depending on where you live.
Several years worth of routine maintenance are executed within a few weeks.
Reset the counters
the number of pages the printer has printed since the last maintenance
The invention of the microprocessor
Your car/van/motorbike
No - insurance is for sudden and accidental damage. Routine repairs are considered maintenance and maintenance is not covered under any insurance policy.
The answer is in the question, Non routine is maintenance which is not done very often like to defrag a hard drive or to replace old hardware. Routine is something that you would do often like virus scans or file management. G.Rudge