A project has the precedence requirements and activity durations shown in the table.After he draws the network,the project manager decides that activities E and F can be represented by a hammock activity.What are the duration and the early start time associated with this hammock activity? $$\begin{array} { | l | l | l | }
\hline & \text { Time } & \text { Predecessor } \
\hline \mathrm { A } & 7 & \
\hline \mathrm { B } & 8 & \mathrm {~A} \
\hline \mathrm { C } & 13 & \mathrm {~B} \
\hline \mathrm { D } & 8 & \mathrm { C } \
\hline \mathrm { E } & 7 & \mathrm {~A} \
\hline \mathrm { F } & 6 & \mathrm { E } \
\hline \mathrm { G } & 6 & \mathrm {~A} \
\hline \mathrm { H } & 11 & \mathrm { G } \
\hline \mathrm { I } & 12 & \mathrm { H } \
\hline \mathrm { T } & 14 & \mathrm { D } , \mathrm { F } , \mathrm { I } \
\hline
\end{array}$$
A) 13, 36
B) 7, 0
C) 13, 7
D) 7, 14

Question

A project has the precedence requirements and activity durations shown in the table.After he draws the network,the project manager decides that activities E and F can be represented by a hammock activity.What are the duration and the early start time associated with this hammock activity? $$\begin{array} { | l | l | l | } 
\hline & \text { Time } & \text { Predecessor } \
\hline \mathrm { A } & 7 & \
\hline \mathrm { B } & 8 & \mathrm {~A} \
\hline \mathrm { C } & 13 & \mathrm {~B} \
\hline \mathrm { D } & 8 & \mathrm { C } \
\hline \mathrm { E } & 7 & \mathrm {~A} \
\hline \mathrm { F } & 6 & \mathrm { E } \
\hline \mathrm { G } & 6 & \mathrm {~A} \
\hline \mathrm { H } & 11 & \mathrm { G } \
\hline \mathrm { I } & 12 & \mathrm { H } \
\hline \mathrm { T } & 14 & \mathrm { D } , \mathrm { F } , \mathrm { I } \
\hline
\end{array}$$
A) 13, 36
B) 7, 0
C) 13, 7
D) 7, 14

Quizplus · Accepted Answer

Activities E and F can be represented as a hammock activity since they both have the same start and end points. The duration of the hammock activity would be the difference between the latest finish time (LFT) of activity E and the earliest start time (EST) of activity F. 
LFT(E) = EST(F) = 36 
Therefore, duration of the hammock activity = LFT(E) - EST(F) = 36 - 29 = 7 
The EST of the hammock activity would be the EST of the earliest of the two activities being combined, which is activity E. 
EST(hammock activity) = EST(E) = 29 
Therefore, the duration and EST of the hammock activity are 7 and 29, respectively. Therefore, the answer is C.

A Project Has the Precedence Requirements and Activity Durations Shown