Critical Path
LGT3105 Operations Management
Semester 2, 2012/13
Individual Written Assignment
(Case 1 Toys City)
Name: LUON Shuk Yan
Student Id: 11280338d
LEC001
SEM 005
Class Instructor: Johnny Wan
Question (1)
I would have accommodated David Cheung’s vacation request.
According to the network diagram above
The critical path of the project is:
Activity 1 Activity 2 Activity 5 Activity 7 Activity 10 Activity 13 Activity 15
As audit of liquid assets (activity 4) is not on the critical path, it is not a critical activity. This slack job has a slack time of 178 hours for which slack time= late start time – early start time (231-53) = late finish time – early finish time (266-88).
The project duration will not be affected even if David takes his one week vacation as the slack time is as long as 178 hours.
The maximum time I would be comfortable giving David Cheung off is 143 hours. (Slack time – duration of his activity = 178 -35). As the latest start time for audit of liquid assets is the 231st hour, the duration of the project will not be affected if David will be back to his work before the 231st hour.
Question (2)
As all the activities were processed exactly on schedule for the first 106 duration hours, the network diagram after the first 106 duration hours is as follow:
The critical path is:
Activity5 Activity7 Activity10 Activity13 Activity15
The remaining duration is 207 hours (= 313 – 106).
We should first calculate the per-unit cost for each hour saved in each activity.
The cost per time unit = Cost to reduce to the minimum
Maximum number of time unit reduced
| | Normal | Acceleration | | | | Activity | Description | Time | Cost($) | Time | Cost($) | Possible time saved | Extra cost | Cost per time unit ($) | 3 | General audit procedures | 22 | 1200 | 22 | 1200 | 0 | 0 | - | 4 | Audit of liquid asset | 35 | 1890 | 35 | 1890 | 0 | 0 | - | 5 | Inventory pricing | 92 | 3055 | 56 |
Semester 2, 2012/13
Individual Written Assignment
(Case 1 Toys City)
Name: LUON Shuk Yan
Student Id: 11280338d
LEC001
SEM 005
Class Instructor: Johnny Wan
Question (1)
I would have accommodated David Cheung’s vacation request.
According to the network diagram above
The critical path of the project is:
Activity 1 Activity 2 Activity 5 Activity 7 Activity 10 Activity 13 Activity 15
As audit of liquid assets (activity 4) is not on the critical path, it is not a critical activity. This slack job has a slack time of 178 hours for which slack time= late start time – early start time (231-53) = late finish time – early finish time (266-88).
The project duration will not be affected even if David takes his one week vacation as the slack time is as long as 178 hours.
The maximum time I would be comfortable giving David Cheung off is 143 hours. (Slack time – duration of his activity = 178 -35). As the latest start time for audit of liquid assets is the 231st hour, the duration of the project will not be affected if David will be back to his work before the 231st hour.
Question (2)
As all the activities were processed exactly on schedule for the first 106 duration hours, the network diagram after the first 106 duration hours is as follow:
The critical path is:
Activity5 Activity7 Activity10 Activity13 Activity15
The remaining duration is 207 hours (= 313 – 106).
We should first calculate the per-unit cost for each hour saved in each activity.
The cost per time unit = Cost to reduce to the minimum
Maximum number of time unit reduced
| | Normal | Acceleration | | | | Activity | Description | Time | Cost($) | Time | Cost($) | Possible time saved | Extra cost | Cost per time unit ($) | 3 | General audit procedures | 22 | 1200 | 22 | 1200 | 0 | 0 | - | 4 | Audit of liquid asset | 35 | 1890 | 35 | 1890 | 0 | 0 | - | 5 | Inventory pricing | 92 | 3055 | 56 |