CPM prob-4

From the following data construct a NWD

Activity	Predecessor	Duration (in days)
A	-	5
B	A	9
C	A	7
D	BC	4
E	A	8
F	DE	14
G	C	12
H	FG	6
I	H	8

Solution

Let us analysis the various nodes.

BC

B & C starts from A; They start from same nodes, and C is repeated, therefore dummy is required from either C to B.

DE

D starts from BC & E starts from A;They start from different nodes, and there is no repetition of E or D,therefore heads of D&E should be merged

FG

F starts from DE & G starts from C;They start from different nodes, and there is no repetition of F or G,therefore heads of F&G should be merged.

NWD diagram

 

Critical path

Path	Duration

Table calculating various matrix

Activity	Duration	EST	EFT	LST	LFT	TF
A (1-2)
B (2-3)
C (2-4)
D (3-5)
E (2-5)
F (5-6)
G (4-6)
H (6-7)
I (7-8)