7 A project is considered completed when activities A–F have all been completed. The duration and predecessors of each activity are given in Table 43. The LINDO output in Figure 69 can be used to determine the critical path for this project.

a Use the LINDO output to draw the project network.

Indicate the activity represented by each arc.

b Determine a critical path in the network. What is the earliest the project can be completed?

FIGURE 69 MIN X6X1 SUBJECT TO 2) X1 X3 >= 3) X4 - X2 >= 4) X3 5) X4 6) -X3 X4 >= X5 >= X5 >= 7) X6 X5 >= 8) X3 X2 >= 31OT550 7 0 9) X1 X2 >= 2 END LP OPTIMUM FOUND AT STEP 3 OBJECTIVE FUNCTION VALUE 15.0000000 1) VARIABLE VALUE REDUCED COST X6 15.000000 0.000000 X1 0.000000 0.000000 X3 3.000000 0.000000 X4 3.000000 0.000000 X2 2.000000 0.000000 X5 ROW 2) 3) 0.000000 4) 0.000000 10.000000 SLACK OR SURPLUS 0.000000 DUAL PRICES -1.000000 0.000000 -1.000000 0.000000 5) 0.000000 -1.000000 6) 2.000000 0.000000 7) 0.000000 -1.000000 8) 1.000000 0.000000 9) 0.000000 0.000000 NO. ITERATIONS= 3