Quantitative Analysis for Management, 13/e

Solved Problems

1. Solved Problem 11-1 To complete the wing assembly for an experimental aircraft, Scott DeWitte has laid out the major steps and seven activities involved. These activities have been labeled A through G in the following table, which also shows their estimated completion times (in weeks) and immediate predecessors. Determine the expected time and variance for each activity.

   ACTIVITY	a	m	b	IMMEDIATE PREDECESSORS
   A	1	2	3	—
   B	2	3	4	—
   C	4	5	6	A
   D	8	9	10	B
   E	2	5	8	C, D
   F	4	5	6	B
   G	1	2	3	E

   Solution

   Although not required for this problem, a diagram of all the activities can be useful. A PERT diagram for the wing assembly is shown in Figure 11.13.

   Figure 11.13 PERT Diagram for Scott DeWitte (Solved Problem 11-1