We must introduce still more terminology before we begin to study scheduling further.

Project
The entire set of tasks to be completed.

Critical Time (of a Project)
The minimum time required to complete the project.

Finishing Time (of a Project)
The actual time required to complete the project.

Schedule
A plan that specifies, for each task in a project, when the task will be done and by which processor.

Scheduling Algorithm
A systematic plan for creating schedules for projects.

Priority List
A list of all the tasks in the order in which the scheduler would prefer to see the tasks done.
Keep in mind that this is just a PREFERENCE!  The order of tasks on the priority list is followed UNLESS it causes a violation of the precedence relations.   Precedence relations override the priority list, but other than that, tasks are assigned to processors according to the priority list.

Optimal Schedule
A schedule with the minimum possible finishing time.
Or, in other words, an optmal schedule for a project is one for which the finishing time is equal to the critical time.

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