Project Management and Project Crash

Project Management Various Topics In this tutorial, we will cover a variety of project management-related topics. First, we will determine the project schedule using single and three time estimates; we will see what is on the critical path, and finally, we will determine the probability of completing the project in a certain amount of time. An electrical contractor is examining the amount of time it takes his crews to complete a wiring job. Some crews take longer than others. For an upcoming job, the table below notes all activities, their optimistic (a), most likely (m), and pessimistic (b) time estimates, and the immediate predecessors.

Activity Optimistic Time (a)

Most Likely Time (m)

Pessimistic Time (b)

Immediate Predecessors

A 3 6 9 -

B 2 4 6 -

C 1 2 3 -

D 6 7 8 C

E 2 4 6 B, D

F 6 10 14 A, E

G 1 2 6 A, E

H 3 6 9 F

I 10 11 12 G

J 14 16 21 G

K 2 8 11 H, I

First, we will go through the example using just the most likely time estimates. Then we will use all three.

For the first example, using a single time estimate, open Excel QM, click on the Excel QM tab  Alphabetical  Project Management  Predecessor List (AON).

A Spreadsheet Initialization window will appear. This time, as shown below, we will select 1 time estimate, 11 activities, and 2 as our max # of predecessors. Leave Graph checked.

Click OK. A spreadsheet table and Gantt Chart will display.

In the Data table, enter the times and predecessors from the table at the beginning of this tutorial. NOTE: you need to enter each predecessor individually in the columns. Once you have correctly entered the data, the results are automatically calculated.

In this example, our project will take 24 days in length and our critical activities are C, D, E, G, J. Excel QM gives us a Gantt chart as a graphical representation of this project:

Click here to download the completed spreadsheet table so you can compare it to yours.

0 5 10 15 20 25 30

K

J

I

H

G

F

E

D

C

B

A

Time

Gantt Chart

Critical Activity Noncritical Activity Slack

If we use our three time estimates, just like before, we open Excel QM, click on the Excel QM tab  Alphabetical  Project Management  Predecessor List (AON). This time, in the Spreadsheet Initialization window, we will select 3 time estimate, 11 activities, and 2 as our max # of predecessors.

You can see from the table below, you need to enter each predecessor individually in the columns.

Once you have correctly entered the data, the results are automatically calculated. We now have a critical path including C-D-E-F-H-K, and an estimated project completion time of 36.5 days with a variance of 5.69 and standard deviation of 2.39 days.

Click here to download the completed spreadsheet table so you can compare it to yours. We can use that information to determine the probability that we finish our project in less than three days using our NORMDIST function using 38 days, our length of 36.5, our standard deviation of 2.39, and 1. Just select any empty cell on your spreadsheet and enter =NORMDIST(38,36.5,2.39,1). Our probability is .7349 that we can complete the project in less than 38 days. This concludes the tutorial on project management various topics.