Question

Often, planned tasks and their duration may change during project execution. It is important to analyze the effect of these changes on your project to ensure that the project still executes as expected. In this assignment, you will learn how to monitor your project for any effect of changes to planned tasks.

Revisit Chapter 6, "Project Time Management" in your textbook. Assume that there are six tasks to be completed in a project. Their duration and predecessors are specified in the following table:

Task	Duration	Predecessors
1.	2 days	N/A
2.	4 days	1
3.	3 days	1
4.	4 days	2
5.	6 days	3
6.	4 days	4, 5

Perform the following tasks:

1. Create a network diagram for this project.

2. Calculate the critical path and slack times for all tasks.

3. Assume that during project execution, you need to change the duration for Task 3 to 5 days, and Task 2 is finished 1 day early. How would these changes affect your project? What problems would have arisen if you were not monitoring the project?

4. Submit the network diagram as an embedded image in a 3- to 4-page document that also contains the calculations for the critical path and slack times and responses to the questions.

Submit your answers in the online classroom by Day 6.

Submit your answers by Day 6.

Answer 1

Network Diagram:

Critical Path:

Possible paths to finish are two as mentioend below along with their completion time:

Paths		Duration
1--> 2 --> 4 --> 6	2+4+4+4	14
1--> 3 --> 5 -->6	2+3+6+4	15

Path 1--> 3 --> 5 -->6 is having longest duration. Hence this is the critical path. This is also the completion time of the project.

The critical tasks are 1,3,5 and 6.

Slack times:

Task	Durations	Predecessors	Earliest Start	Earliest Finish	Late Start	Late Finish	Slack Time
1	2	NA	0	2	0	2	0
2	4	1	2	6	3	7	1
3	3	1	2	5	2	5	0
4	4	2	6	10	7	11	1
5	6	3	5	11	5	11	0
6	4	4, 5	11	15	11	15	0

Excel Formulae for the slack time calculations:

Earliest start time = earliest finish time of predecessor.

If there are two predecessors then the earliest start time would be the maximum earliest finish time of predecessors. (an example is task 6)

the earliest start time of task 6 is max (10,11) i.e max (task 4 and task 5). hence the value is 11.

Late finish and start times are calculated backward from the task 6 to task 1.

Late FInish time = Late start time of its successor

If there are two successors as in the case of task 1, the late finish time is the minimum of late start times of its successors. Min (3,2) i.e min of late starts of task 2 and task 3.

Slack Time for each activity = Late Finish Time - Earliest Finish Time or Late Start Time - Earliest Start Time

For critical tasks, the slack time is 0. This means if the duration of these tasks is changed, the completion time of the project gets affected.

For noncritical tasks, the slack time represents the extent of change the task duration can be changed without affecting the project completion time with in the amount of slack time available.

Task 3 is a critical task and Task 2 is a noncritical task.

Hence if the duration of task 3 is made 5 days i.e it is increased by 2 days, then the project completion time also increases by 2 days.

And if task 2 is finished 1 day early i.e the duration is reduced by 1 day, then it does not affect the project completion time as slack time is 1.

The new path durations are:

Paths		Duration
1--> 2 --> 4 --> 6	2+3+4+4	13
1--> 3 --> 5 -->6	2+5+6+4	17

The new project completion time is 17 days as compared to the previous time 15 days. It has been increased by 2 days

If the project would have not been monitored and the duration of task 3 was increased to 5 days, the project completion would have been delayed affecting the planning, and cost.