Question

One internal carpentry crew One external carpentry crew One plumbing crew

They are working concurrently on the jobsite to perform the following construction activities with the estimated durations provided below.

§ Construction activity

Days § Frame exterior Stud Walls 4
§ Place sheathing on exterior walls 1
§ Frame interior stud walls 2
§ Install exterior wall-mounted plumbing fixtures 5

What is the minimum number of workdays (effective days)?

A 1

B 9

C 11

D 12

I picked 12 because its asking workable days, why is it not 12?

Answer 1

Ans: Minimum number of workdays are 9 days .

Because when we take each activity Framing take 4 days , while framing we can use early start condition i.e., when one worker framing the wall then the other will sheathing to that wall. So both activities simultaneously take only 4 days , and once the framing completed then Fixing of plumbing fixtures take 5 days then there we can done internal wall framing. By this the effective days that can require to complete this activities is 9 days.

And when it comes to question why its not 12 days , by the early start and early finish we can comlete the above work in maximun of 9 days. So there is no need of considering each activity period separately.