Question

The home billing department of a department stores prepares monthly inventory reports for use by the stores’ purchasing agents. Given the following information, use the critical path method to determine-

Job & Description                                                            Immediate                                  Time

Predecessors                          (Hours)

1.         Start                                                                                             —                            0

2.         Get computer printouts of customer purchases                  A                             4

3.         Get stock records for the month                                          A                                 15

4.         Reconcile purchase printouts and stock records               B, C                         18

5.         Total stock records by department                                    B, C                             4

6.         Determine reorder quantities for coming period                 E                            14

7.         Prepare stock reports for purchasing agents                     D, F                            4

8.         Finish                                                                                            G                               1

How long will the total process take?   # Of Hours:­­­________________

Which jobs can be delayed without delaying the early start of any subsequent activity?

E & F

C & D

C & E

B

Answer 1

step 1	find early start, and early finish from the start of the project for each activity
step 2	Find Maximum EF and keep it as the LF of last activities. Max of EF's is 37

Activity	Duration, D	Early start, ES=Max of early finish of preceding activities	Early finish, EF = ES + D	Late finish, LF= Min of LS of successor activities	Late start, LS= LF - D	Total slack= LF- EF	Critical activity, activities with 0 slack time
A	0	0	0
B	4	0	4
C	15	0	15
D	18	15	33
E	4	15	19
F	14	19	33
G	4	33	37
H	1	37	38

step 3

calculate LS for each activity after calculating its EF

Activity	Duration, D	Early start, ES=Max of early finish of preceding activities	Early finish, EF = ES + D	Late finish, LF= Min of LS of successor activities	Late start, LS= LF - D	Total slack= LF-EF	Critical activity, activities with 0 slack time
A	0	0	0	0	0	0	Yes
B	4	0	4	15	11	11	No
C	15	0	15	15	0	0	Yes
D	18	15	33	33	15	0	Yes
E	4	15	19	19	15	0	Yes
F	14	19	33	33	19	0	Yes
G	4	33	37	37	33	0	Yes
H	1	37	38	38	37	0	Yes

It will take 38 hours in a process.

jobs can be delayed without delaying the early start of any subsequent are the non critical path activities.

Activity B