Hi would someone please help me with the following problem, this way I will understand how I can do it myself I missed class due to being ill...
Calculate the earliest starting time, the latest starting time (EST,LST) and the earliest finishing time and latest finishing time (EFT, LFT) for each activity including
an outline description of the critical path, highlighting the critical activities and the shortest possible time in days in which the project can be
completed as scoped above. (give reasons for your choice)
The activities are as follows here:
No Activity Duration(days) Predecessor
1 A 1 -
2 B 14 1
3 C 14 1
4 D 7 2
5 E 7 4
6 F 28 5
7 G 42 3,6
8 H 12 3,6
9 I 2 5
10 J 84 9
11 K 7 1
12 L 7 11
13 M 35 6,9,11
14 N 1 13
15 O 5 14
16 P 7 6
17 Q 21 16
18 R 4 12
19 S 7 9
20 T 5 7,19
21 U 1 8,10,18,20
22 V 10 15,17,21
Thanks a lot
To calculate the earliest starting time (EST), latest starting time (LST), earliest finishing time (EFT), and latest finishing time (LFT) for each activity, you can use the Critical Path Method (CPM). CPM is a project management technique that helps in determining the critical activities and the shortest possible time to complete a project.
Here's how you can approach this problem:
1. Create a table with the following columns: Activity, Duration, Predecessor, EST, LST, EFT, LFT.
2. Start by filling in the Duration and Predecessor columns for each activity based on the given information.
3. Begin with Activity 1 and assign an EST of 0 since it has no predecessors.
4. Move to the next activity and calculate its EST by finding the maximum EST of its predecessors plus their respective durations. Repeat this step for all activities.
5. Once you have calculated the EST for each activity, calculate the EFT by adding the Duration to the EST.
6. Now, start from the last activity and assign an LFT equal to its EFT.
7. Move to the previous activities and calculate their LST by subtracting their respective durations from the minimum LFT of their successors. Repeat this step for all activities.
8. Finally, calculate the LFT for each activity by adding the Duration to the LST.
To find the critical path and the shortest possible time to complete the project, you need to identify the activities with the same EST and LST values. These activities are critical as any delay in their completion will delay the project.
To summarize, follow these steps:
1. Create a table with columns: Activity, Duration, Predecessor, EST, LST, EFT, LFT.
2. Fill in the Duration and Predecessor columns based on the given information.
3. Calculate the EST for each activity by finding the maximum EST of its predecessors plus their respective durations.
4. Calculate the EFT for each activity by adding the Duration to the EST.
5. Assign an LFT equal to the EFT for the last activity.
6. Calculate the LST for each activity by subtracting their respective durations from the minimum LFT of their successors.
7. Calculate the LFT for each activity by adding the Duration to the LST.
8. Identify the activities with the same EST and LST values as critical activities.
9. The sum of the critical activities' durations represents the shortest possible time in days to complete the project.
Follow these steps for the activities you provided, and you'll be able to determine the critical path and the shortest possible time to complete the project.