2. Explain how you determined the timing of activities and the total float.
From the work of Field and Keller (1998), there are some relationships among EST, EFT, LST, LFT, duration and TF in an activity-on-node. (See Table 1) Meanwhile, there are some types of dependency, but finish-to-start lag is normal one. In the network diagram drawn, it uses the finish-to-start relationship.
Earliest Finish Time(EFT) = Earliest Start Time(EST) + Duration
Latest Start Time(LST) = Latest Finish Time(LFT) - Duration
Total Float(TF) = Latest Finish Time(LFT) - Earliest Start Time(EST) - Duration
Table 1: The relationships among EST, EFT, Duration, LST, LFT and TF (Field and Keller, 1998, pp.197-202)
In terms of the timing of activities, Maylor (2003) thinks that it includes the forward pass and reverse pass. In forward pass, it begins at the left-hand side of the diagram with the earliest start time for the initial activity, which is zero. The next activity cannot begin until the first activity has completed. So the early start of activity A is zero. Owing to 4 days duration, the earliest finish time of activity A is 4 days. Adding the duration of each activity, EFT of final activity Q is 88 days. In reverse pass, it begins from the end of the network i.e. 88 days and allocates the LSTs for each activity. According to Turner (1999), in the back pass, the early finish of last activity transfers to its late finish. Total float equals to late start date minus early start date.
3. Explain how you determined the project duration and the critical path.
According to Gray & Larson (2006), they think that the earliest finish time of the final activity of project in the forward pass is identified as the project duration through beginning at the first activity and then adding the activity duration. In the network diagram drawn, the project duration is 88 days.
In the work of Turner (1999), the critical path