| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Year | 2022 |
| Session | January |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Critical Path Analysis |
| Type | Draw activity network from table |
| Difficulty | Moderate -0.8 This is a straightforward activity network drawing question requiring only systematic application of precedence rules. While it has multiple activities and dependencies, it's a standard D1 exercise with no problem-solving or optimization required—just careful diagram construction following the given table. |
| Spec | 7.05a Critical path analysis: activity on arc networks |
| Activity | Immediately preceding activities |
| A | - |
| B | - |
| C | - |
| D | A, B, C |
| E | A, B, C |
| F | C |
| G | F |
| H | D |
| I | D, E, G |
| J | D, E |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| Seven activities labelled on arcs, one start, at least two dummies placed | M1 | If one arc not labelled loses first A mark and final CSO A mark |
| Activities A, B, C; first two dummies (with correct arrows on dummies) and F dealt with correctly | A1 | First two dummies at end of A (or B if A and B interchanged) and C |
| D, E, G and H dealt with correctly | A1 | Can be scored on bod if arrows missing off first two dummies provided dummies in correct place |
| I and J dealt with correctly – requires third and fourth dummies (including correct arrows) | A1 | |
| All arrows correctly placed for each activity with one finish and at most four dummies | A1 | cso – must have scored first four marks; additional unnecessary correct dummies only penalised with final A mark |
# Question 3:
| Answer | Marks | Guidance |
|--------|-------|----------|
| Seven activities labelled on arcs, one start, at least two dummies placed | M1 | If one arc not labelled loses first A mark and final CSO A mark |
| Activities A, B, C; first two dummies (with correct arrows on dummies) and F dealt with correctly | A1 | First two dummies at end of A (or B if A and B interchanged) and C |
| D, E, G and H dealt with correctly | A1 | Can be scored on bod if arrows missing off first two dummies provided dummies in correct place |
| I and J dealt with correctly – requires third and fourth dummies (including correct arrows) | A1 | |
| All arrows correctly placed for each activity with one finish and at most four dummies | A1 | cso – must have scored first four marks; additional unnecessary correct dummies only penalised with final A mark |
**Note:** Solution is not unique e.g. A and B could be interchanged
---3.
\begin{center}
\begin{tabular}{|l|l|}
\hline
Activity & Immediately preceding activities \\
\hline
A & - \\
\hline
B & - \\
\hline
C & - \\
\hline
D & A, B, C \\
\hline
E & A, B, C \\
\hline
F & C \\
\hline
G & F \\
\hline
H & D \\
\hline
I & D, E, G \\
\hline
J & D, E \\
\hline
\end{tabular}
\end{center}
\section*{Question 3 continued}
Please redraw your activity network on this page if you need to do so.\\
\hfill \mbox{\textit{Edexcel D1 2022 Q3 [5]}}