Chapter 11, Problem 21RE

(a)

To determine

The kind of scheduling problem. If Dan and Jeff decided to cook a meal for their friends. The table shows the tasks involved and the time each requires. The food must be bought first, and all chopping of vegetables for the salad has to be done before making the salad. Similarly, all chopping of vegetables for the stir fry must be done before cooking the stir fry. The chicken wings can be cooked anytime (after purchase), while the rice must be cooked before it is drained. The stir-fry will sit on the rice, so the rice must be drained before the stir fry is cooked. Finally, everything is arranged on the plates.

Task	Code	Units of Time
Buy groceries	B	10
Cook chicken	W	8
Chop vegetables for salad	CVS	3
Chop vegetables for stir fry	CVF	2
Cook rice	R	4
Cook stir fry	SF	7
Make salad	S	1
Drain rice	DR	1
Arrange plates	A	1

(b)

To determine

To graph: A network that illustrates the routes to completion of dinner preparations. Apply Dijkstra’s algorithm (first version) to your network to find the shortest time that Dan and Jeff must allow to prepare dinner.

(c)

To determine

The critical path and slack also the number of slack in each case.