| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Year | 2019 |
| Session | June |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Critical Path Analysis |
| Type | Identify guaranteed critical activities |
| Difficulty | Moderate -0.8 This is a straightforward Critical Path Analysis question requiring standard techniques: drawing a network with specified dummies (routine but mechanical), explaining why I or J must be critical (basic logic about network structure), and identifying guaranteed critical activities given C is critical (following precedence chains). All parts are textbook applications with no novel problem-solving required. |
| Spec | 7.05a Critical path analysis: activity on arc networks |
| Activity | Immediately preceding activities |
| A | - |
| B | - |
| C | A |
| D | A |
| E | A, B |
| F | C, D |
| G | D |
| H | D, E |
| I | F, G |
| J | F, G, H |
5.
\begin{center}
\begin{tabular}{|l|l|}
\hline
Activity & Immediately preceding activities \\
\hline
A & - \\
\hline
B & - \\
\hline
C & A \\
\hline
D & A \\
\hline
E & A, B \\
\hline
F & C, D \\
\hline
G & D \\
\hline
H & D, E \\
\hline
I & F, G \\
\hline
J & F, G, H \\
\hline
\end{tabular}
\end{center}
\begin{enumerate}[label=(\alph*)]
\item Draw the activity network described in the precedence table above, using activity on arc and exactly 4 dummies.
\item Explain why one of the activities I or J must be critical.
It is given that activity C is a critical activity.
\item State the activities that are therefore guaranteed to be critical.
\end{enumerate}
\hfill \mbox{\textit{Edexcel D1 2019 Q5 [7]}}