| Exam Board | AQA |
|---|---|
| Module | Further Paper 3 Discrete (Further Paper 3 Discrete) |
| Year | 2022 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Critical Path Analysis |
| Type | Effect of activity delay/change |
| Difficulty | Standard +0.3 This is a standard critical path analysis question requiring routine application of forward and backward passes to find earliest/latest times, identifying critical activities, and basic reasoning about which activity to crash. While it involves multiple steps, these are algorithmic procedures commonly practiced in Further Maths discrete modules with no novel problem-solving required. |
| Spec | 7.05a Critical path analysis: activity on arc networks7.05b Forward and backward pass: earliest/latest times, critical activities7.05c Total float: calculation and interpretation |
| Answer | Marks | Guidance |
|---|---|---|
| 6(a)(i) | Finds correctly the earliest start | |
| time for activities E, G and H | 1.1a | M1 |
| Answer | Marks | Guidance |
|---|---|---|
| on the network | 1.1b | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| activity | 1.1b | B1 |
| Total | 3 | |
| Q | Marking instructions | AO |
| Answer | Marks | Guidance |
|---|---|---|
| 6(a)(ii) | Identifies correctly all critical | |
| activities and no others | 1.1b | B1 |
| Total | 1 | |
| Q | Marking instructions | AO |
| Answer | Marks | Guidance |
|---|---|---|
| 6(b) | Identifies that activity J should | |
| have its duration reduced | 3.2a | M1 |
| Answer | Marks | Guidance |
|---|---|---|
| the project by 2 weeks | 2.4 | R1 |
| Total | 2 | |
| Question total | 6 | |
| Q | Marking instructions | AO |
Question 6:
--- 6(a)(i) ---
6(a)(i) | Finds correctly the earliest start
time for activities E, G and H | 1.1a | M1
Finds correctly the earliest start
time for activities each activity
on the network | 1.1b | A1
Finds correctly the latest finish
time for each activity on the
network
Condone inclusion of ‘END’
activity | 1.1b | B1
Total | 3
Q | Marking instructions | AO | Marks | Typical solution
--- 6(a)(ii) ---
6(a)(ii) | Identifies correctly all critical
activities and no others | 1.1b | B1 | B, F, H, J, L
Total | 1
Q | Marking instructions | AO | Marks | Typical solution
--- 6(b) ---
6(b) | Identifies that activity J should
have its duration reduced | 3.2a | M1 | Activity J should be selected, as a
2 week reduction in the duration of
J will result in a 2 week reduction in
the minimum completion time for
the project.
Explains that reducing activity
J’s duration by 2 weeks reduces
the minimum completion time for
the project by 2 weeks | 2.4 | R1
Total | 2
Question total | 6
Q | Marking instructions | AO | Marks | Typical solutionBill Durrh Ltd undertake a construction project.
The activity network for the project is shown below. The duration of each activity is given in weeks.
\includegraphics{figure_7}
\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Find the earliest start time and the latest finish time for each activity and show these values on the activity network above.
[3 marks]
\item Identify all of the critical activities.
[1 mark]
\end{enumerate}
\item The manager of Bill Durrh Ltd recruits some additional temporary workers in order to reduce the duration of one activity by 2 weeks.
The manager wants to reduce the minimum completion time of the project by the largest amount.
State, with a reason, which activity the manager should choose.
[2 marks]
\end{enumerate}
\hfill \mbox{\textit{AQA Further Paper 3 Discrete 2022 Q6 [6]}}