| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Critical Path Analysis |
| Type | Draw activity network from table |
| Difficulty | Moderate -0.8 This is a standard D1 activity network construction question requiring application of a well-practiced algorithm. Students follow mechanical rules for precedence tables, node numbering, and dummy activities. While worth 7 marks, it involves routine procedural work rather than problem-solving or insight, making it easier than average A-level questions. |
| Spec | 7.05a Critical path analysis: activity on arc networks7.05b Forward and backward pass: earliest/latest times, critical activities |
| Activity | Depends on | Duration (hours) |
| \(A\) | \(-\) | 5 |
| \(B\) | \(A\) | 4 |
| \(C\) | \(A\) | 2 |
| \(D\) | \(B, C\) | 11 |
| \(E\) | \(C\) | 4 |
| \(F\) | \(D\) | 3 |
| \(G\) | \(D\) | 8 |
| \(H\) | \(D, E\) | 2 |
| \(I\) | \(F\) | 1 |
| \(J\) | \(F, G, H\) | 7 |
| \(K\) | \(I, J\) | 2 |
| Answer | Marks | Guidance |
|---|---|---|
| e.g. [Activity network diagram with nodes 0-9 and labeled edges showing duration and float values] | M3 A4 | (7) |
e.g. [Activity network diagram with nodes 0-9 and labeled edges showing duration and float values] | M3 A4 | (7) |
---A project consists of 11 activities, some of which are dependent on others having been completed. The following precedence table summarises the relevant information.
\begin{center}
\begin{tabular}{|c|c|c|}
\hline
Activity & Depends on & Duration (hours) \\
\hline
$A$ & $-$ & 5 \\
$B$ & $A$ & 4 \\
$C$ & $A$ & 2 \\
$D$ & $B, C$ & 11 \\
$E$ & $C$ & 4 \\
$F$ & $D$ & 3 \\
$G$ & $D$ & 8 \\
$H$ & $D, E$ & 2 \\
$I$ & $F$ & 1 \\
$J$ & $F, G, H$ & 7 \\
$K$ & $I, J$ & 2 \\
\hline
\end{tabular}
\end{center}
Draw an activity network for the project. You should number the nodes and use as few dummies as possible. [7 marks]
\hfill \mbox{\textit{Edexcel D1 Q2 [7]}}