Refer to Table 3 below (reproduced from the insert) and the network diagram on the opposite page. Table 3: Estimated times for activities for building and equipping the new factory Activity | Duration (weeks) | Preceding activities ---|---|--- A | Plan new building and employ building contractor | 8 | None B | Remove existing building | 2 | A C | Clear and prepare the site | 1 | B D | Deliver building materials to site | 1 | A E | Complete building work | 4 | C, D F | Connect water supply and electricity | 2 | E G | Install machinery | 3 | E H | Recruit new workforce | 4 | A J | Train workforce on site | 1 | F, G, H. [Network diagram on page 11 showing activities A-J and nodes 1-7 to be completed with EST/LFT values]

Mark scheme

Marking points from the official mark scheme (Feb/Mar 2018). The mark or mark type is shown in brackets.

1. 1 mark per correct node
2. 3 marks if all ESTs correct
3. 3 marks if all LFTs correct
4. OFR
5. Critical path is A,B,C,E,G,J
6. Note: It is not necessary to redraw the network diagram, but credit candidates who have included answers on their own drawn diagram.
7. CPA or network diagram is a way of sequencing activities and identifying which may not be delayed without delaying the whole project.
8. Needs to be drawn up using expert information and realistic estimates of time taken. May be time consuming to carry out.
9. Useful to work out which activities may be carried out at the same time
10. May mean that resources, are ordered when needed and do not have to be kept for a long time before use.
11. But does not take account of unforeseen delays.
12. Reference to particular tasks which may/may not be easy to predict the duration, e.g. installation of services such as water
13. Reference to reasons for delays, for example bad weather delaying building work or unreliable suppliers of building materials
14. Possible lack of expertise in AP for planning this type of building project, due to lack of knowledge of local conditions in Africa.
15. Reference to importance of activities on the critical path
16. Line of argument followed as to how a network diagram may help to plan and sequence activities, avoid waste of time and resources
17. Line of argument as to why/how this may be difficult to predict and the consequences, if a critical activity is delayed, this will delay the whole project and lead to increased costs.
18. Only as accurate as information and expertise used to compile it.
19. A useful tool, along with local knowledge, e.g. in African environment in this case.