Which of the following is NOT true about the waiting time of a process?

Waiting time is an important metric in operating systems that measures how long a process has been in a ready state, waiting for CPU time to be allocated to it.

The statement that the waiting time of a process is counted from the submission to completion of a process is not accurate. Waiting time specifically refers to the duration a process is in the queue awaiting CPU assignment and does not include the time the process spends being executed (runtime) or the time it spends actively using resources.

To clarify, while a process is running, that time is not considered waiting time; rather, it is part of the process's execution time. This delineation is crucial for understanding performance metrics and improving process scheduling within an operating system.

In contrast, the other statements highlight aspects of waiting time that are indeed true. For example, it does occur while waiting for resources, it can include time scheduled for execution if the process is preempted, and it does not account for execution time or time spent when a process is already in a running state.