| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Year | 2022 |
| Session | June |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Critical Path Analysis |
| Type | Draw activity network from table |
| Difficulty | Moderate -0.8 This is a routine D1 critical path analysis question requiring standard techniques: drawing an activity network from a precedence table (which follows algorithmic rules for dummy placement) and reading values from a provided Gantt chart. No problem-solving or novel insight required—pure procedural application of well-practiced methods. |
| Spec | 7.05a Critical path analysis: activity on arc networks7.05b Forward and backward pass: earliest/latest times, critical activities7.05d Latest start and earliest finish: independent and interfering float |
| Activity | Immediately preceding activities |
| A | - |
| B | - |
| C | - |
| D | A, B |
| E | A, B |
| F | B, C |
| G | B, C |
| H | D |
| I | D, E, F, G |
| J | H, I |
| K | D, E, F |
5. The precedence table shows the eleven activities required to complete a project.
\begin{center}
\begin{tabular}{|l|l|}
\hline
Activity & Immediately preceding activities \\
\hline
A & - \\
\hline
B & - \\
\hline
C & - \\
\hline
D & A, B \\
\hline
E & A, B \\
\hline
F & B, C \\
\hline
G & B, C \\
\hline
H & D \\
\hline
I & D, E, F, G \\
\hline
J & H, I \\
\hline
K & D, E, F \\
\hline
\end{tabular}
\end{center}
\begin{enumerate}[label=(\alph*)]
\item Draw the activity network for the project, using activity on arc and the minimum number of dummies.\\
(5)
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{27296f39-bd03-47ff-9a5e-c2212d0c68ed-07_314_1385_1464_347}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}
Figure 3 shows a schedule for the project. Each of the activities shown in the precedence table requires one worker. The time taken to complete each activity is in hours and the project is to be completed in the minimum possible time.
\item \begin{enumerate}[label=(\roman*)]
\item State the minimum completion time for the project.
\item State the critical activities.
\item State the total float on activity G and the total float on activity K .\\
(4)
\end{enumerate}\end{enumerate}
\hfill \mbox{\textit{Edexcel D1 2022 Q5 [9]}}