The GATE Grind

GATE 2017 CE (CE1) – Question 55

Construction Management · Project planning and scheduling: AOA and AON, PERT and CPM · 2 marks · Numerical answer

A project has activities with predecessors and durations in days: P (none, 6); Q (P, 15); R (Q and T, 12); S (R, 16); T (P, 10); U (Q and T, 14); V (U, 16). Find the minimum project completion time in days.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 51 to 51

Explanation

Forward-pass earliest finishes are P 6, Q $6+15=21$, and T $6+10=16$. R and U must both wait for Q and T, so they start at $\max(21,16)=21$. Then R finishes at 33 and S at 49; U finishes at 35 and V at 51. Both terminal activities must finish, so project duration is $\max(49,51)=51$ days, on critical path P–Q–U–V.

More Project planning and scheduling: AOA and AON, PERT and CPM questions

All Project planning and scheduling: AOA and AON, PERT and CPM questions →