3.11

Dave Fletcher (see Problem 3.10) was able to determine
the activity times for constructing his laser scanning
machine. Fletcher would like to determine ES, EF, LS, LF, and
slack for each activity. The total project completion time and
the critical path should also be determined. Here are the activity
times:

ACTIVITY TIME (WEEKS) ACTIVITY TIME (WEEKS) (letter is activity and number is time)

A6       E 4
B 7       F 6
C 3      G 10
D 2       H 7

3.17

Bill Fennema, president of Fennema Hospitality, has

developed the tasks, durations, and predecessor relationships in

the following table for building new motels. Draw the AON network

and answer the questions that follow.

Activity   predecessor optimistic       Most       pessimistic

                                                                likely       OPTIMISTIC

MOST

LIKELY PESSIMISTIC

A        —      4       8        10

B       A        2       8         24

C       A        8      12       16

D       A        4       6         10

E       B         1      2         3

F       E,C      6       8        20

G     E, C     2      3         4

H       F          2      2         2

I        F          6      6         6

J      D,G,H    4     6        12

K      I,J         2      2        3

c) Based on the calculation of estimated times, what is the critical

path?

d) What is the estimated time of the critical path?

e) What is the activity variance along the critical path?

f) What is the probability of completion of the project before

week 36?

to be completed in excel on seperate pages