Answer to Question #272124 in Operations Research for Prathibha Rose

Question

Consider a project consisting of nine jobs (A, B, C,….,I) with the following precedence 

relations and time estimates.

Job Predecessor Time (Days)

A -- 15

B -- 10

C A,B 10D AB 10

E B 5

F DE 5

G CF 20 

H DE 10

I GH 15

Answer 1

project network:

graph constructed by principle: if job A is predecessor of job B, then arrow goes from node A to node B

so,

A, B are predecessors of C and D: arrows from A to C and D, and from B to C and D

B is predecessor of E: arrow from B to E

D, E are predecessors of F: arrows from D to F, and from E to F

C, F are predecessors of G: arrows from C to G, and from F to G

D, E are predecessors of H: arrows from D to H, and from E to H

G, H are predecessors of I: arrows from G to I, and from H to I