Complete nodes 5 and 6 on the network diagram below (reproduced from the Insert). [Figure 1]

Mark scheme

Marking points from the official mark scheme (Feb/Mar 2025). The mark or mark type is shown in brackets.

1. [1] (a) EST of G = 9
2. [1] (a) LFT of D = 8
3. [1] (b) Total float = LFT (of F) – Duration (of F) – EST (of F)
4. [1] (b) OR Total Float = LST – EST (1 mark if no rewardable calculation)
5. [1] (b) Total float = 9 – 1 – 4
6. [1] (b) OR 8 – 4
7. [2] (b) = 4 (weeks) (Incorrect units e.g. 4 days (1))
8. [1] (c) Knowledge: Understanding of CPA – network diagram, critical path, floats, minimum duration.
9. [1] (c) Knowledge: Benefits of CPA: knowing minimum project time, start times for activities, progress monitoring, assessing significance of delays and if necessary, corrective actions.
10. [1] (c) Knowledge: Limitations of CPA: analysis only as good as input data, planning costs, does not ensure effective management.
11. [1] (c) Application: Operations Director produced the CPA.
12. [1] (c) Application: 24-week minimum time.
13. [1] (c) Application: Disruption to production during works.
14. [1] (c) Application: Delivery of machinery is from Europe.
15. [1] (c) Application: Expansion involves building work – where is data on timings from?
16. [1] (c) Application: Use of data in Fig 1 and answers to 4(a) and 4(b).
17. [1] (c) Application: Total float of activity F.
18. [1] (c) Application: Free float of activity F.
19. [1] (c) Application: Activity E and G are critical activities.
20. [1] (c) Analysis: CPA is a quantitative technique and more exact than estimation. Planning will help save resources and ensure that disruption is minimised reducing IPA's expansion.
21. [1] (c) Analysis: CPA will enable IPA to get back to full production as soon as possible and therefore manage cash flow more effectively.
22. [1] (c) Analysis: Important to use CPA so that customers can be kept informed of any potential impact on orders. This will help avoid customer dissatisfaction which could result in loss of sale.
23. [1] (c) Evaluation: Justified conclusion on importance e.g. CPA very important for enabling continuous supply.
24. [1] (c) Evaluation: Monitoring the most critical activities such as the machinery from Europe as this could be delayed due to external factors.
25. [1] (c) Evaluation: CPA only as good as data – is the Operations Director capable of completing accurate CPA for the factory development?
26. [1] (c) Evaluation: Other information is also important e.g. CPA needs to be interpreted.
27. [1] (c) Evaluation: Work progress must match the CPA plan.
28. [1] (c) Evaluation: IPA would be wise to maintain constant check on progress before and after work starts.