Question

Activity Code	Immediate Predecessors	Activity Duration (Week)
A	None	3
B	A	3
C	A	2
D	C	2
E	B&C	3
F	B	2
G	D&E	1
H	G	4
I	F	7
J	H&I	2
K	J	4
L	F	6

Activity Code	Early Start	Early Finish	Late start	Later Finish	Total Float
A	0	3	0	3	0
B	3	6	3	6	0
C	3	5	5	7	2
D	5	7	8	10	3
E	6	9	7	10	1
F	6	8	6	8	0
G	9	10	10	11	1
H	10	14	11	15	1
I	8	15	8	15	0
J	15	17	15	17	0
K	17	21	17	21	0
L	8	14	15	21	7

the Critical Path is A-B-F-I-J-K=21    

1-)If all critical path activities were crashed by 25%, calculate the new overall project duration?

Answer 1

Activity Code	Reduced Duration	Early Start	Early Finish	Late start	Later Finish	Total Float
A	2.25	0	2.25	0	2.25	0
B	2.25	2.25	4.5	2.25	4.5	0
C	2	2.25	4.25	2.5	4.5	0.25
D	2	4.25	6.25	5.5	7.5	1.25
E	3	4.5	7.5	4.5	7.5	0
F	1.50	4.5	6	5.75	7.25	1.25
G	1	7.5	8.5	7.5	8.5	0
H	4	8.5	12.5	8.5	12.5	0
I	5.25	6	11.25	7.25	12.5	1.25
J	1.50	12.5	14	12.5	14	0
K	3	14	17	14	17	0
L	6	6	12	11	17	5

So,

After reducing all the critical path activities by 25%, a new critical path emerges i.e. A-B-E-G-H-J-K.

The project duration will be 17 weeks