Large Number of Heuristics

Heuristic schedules are built by applying the selected heuristic (rule), such as "least total slack," to each task assignment decision. A rule can be implemented in several ways:

• Using dynamic or static allocation (depending on whether task properties are recalculated after each task assignment);

• Using forward or backward allocation (depending on whether the project sequence is built from the start or end of the project);

• Using serial or parallel allocation (depending on whether the tasks are sequenced strictly in order of the heuristic priority, or whether the schedule is built in chronological order with conflicts decided by the selected rule); and

• Allowing tasks to be split or not.

So there are 24, or 16, ways to implement a single rule if no ties occur. Ties often do occur: such as when two or more tasks have the same total slack. To break a tie, another rule such as "shortest imminent task" or "earliest late finish" can be used. If a tie still ensues, a third rule can be used. The use of four tie-breaking rules increases the number of distinct implementations by a factor of 41 to 384.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

Get My Free Ebook


Post a comment