2 The diagram below shows an activity network for a project. The figures in brackets show the durations of the activities, in hours.\\
\includegraphics[max width=\textwidth, alt={}, center]{b3a3d522-2ec9-46ec-bd99-a8c698e3d1c0-3_371_1429_367_319}
\begin{enumerate}[label=(\roman*)]
\item Complete the table in your answer book to show the immediate predecessors for each activity.
\item Carry out a forward pass and a backward pass on the copy of the network in your answer book, showing the early event times and late event times. State the minimum project completion time, in hours, and list the critical activities.
\item How much longer could be spent on activity $F$ without it affecting the overall completion time?

Suppose that each activity requires one worker. Once an activity has been started it must continue until it is finished. Activities cannot be shared between workers.
\item (a) State how many workers are needed at the busiest point in the project if each activity starts at its earliest possible start time.\\
(b) Suppose that there are fewer workers available than given in your answer to part (iv)(a). Explain why the project cannot now be completed in the minimum project completion time from part (ii).

Suppose that activity $C$ is delayed so that it starts 2 hours after its earliest possible start time, but there is no restriction on the number of workers available.
\item Describe what effect this will have on the critical activities and the minimum project completion time.
\end{enumerate}

\hfill \mbox{\textit{OCR D2 2015 Q2 [12]}}