# Interactive: Project Schedule Network Diagramming

## You should know and understand the Fundamental concepts of Project Network Diagramming as presented in Chapter 6 of the PMBOK and the PMP Exam Content Outline available from www.pmi.org

### Which activities are on the Critical Path?

#### A-C-G = 15 days, which is the Critical Path

Click on the desired activities with your mouse to select them.

### Which activities have 4 days of Float?

#### Activities B & D both have 4 days of Float.

Click on the desired activities with your mouse to select them.

### Which activity must be completed no later than day 9?

#### Activity C must be completed no later than day 9

Click on the desired activity with your mouse to select it.

### Which activity can start as early as day 4 and finish as late as day 12 using the "Start at 0" Forward Pass & Backward Pass method?

#### Activity E can start as early as day 4 and end as late as day 12

Click on the desired activity with your mouse to select it.

### If the start of activity D was delayed by 4 days due to a late delivery of materials, which activities would be on the Critical Path?

#### The project would now have 2 Critical Pathways:A-C-G = 15 daysB-D-G = 15 days

Click on the desired activities with your mouse to select them.

### If this project started on June 10th, what is the earliest day could it be completed?

#### The Critical Path is A-C-G = 15. If every day is a work day, and the project started on June 10th, it would be completed 15 days later on June 24th. Remember, June 10th counts as a work day.

• June 25th
• June 24th
• July 1st
• June 21st

Every day is a work-day.

### Which activities are on the Critical Path?

#### B-D-G = 18, which is the Critical Path

Click on the desired activities with your mouse to select them.

### Which activities have 6 days of Float?

#### Activities A and F both have 6 days of Float.

Click on the desired activities with your mouse to select them.

### Which activity has 3 days of Free Float?

#### Activity A has 3 days of Free Float, but 6 days of Total Float. Free Float is the amount of time an activity can be delayed without affecting the Early Start date of any successor activity, in this case activity E.

Click on the desired activity with your mouse to select it.

### Which activities must be completed no later than day 12?

#### Both activities E and D must be completed by day 12 in order to start Critical Path activity G no later than day 12.

Click on the desired activities with your mouse to select them.

• 4
• 5
• 6
• 7

### If this project started on April 2nd, what is the earliest day it could be completed?

#### The Critical Path is B-D-G = 18 days. If every day is a work day, and the project starts on April 2nd, it will be done 18 days later on April 19th. Remember, April 2nd counts as a work day.

• April 18th
• April 19th
• April 20th
• April 17th

Every day is a work-day.

### Which activities are on the Critical Path?

#### Ok, this one is  a bit more difficult and doesn't follow the same rules as a diagram with all FS relationships. Notice that there is an FF relationship between activities C & D with 2 days of lag as indicated by the FF-2. This means that activity D must finish 2 days before activity C finishes. Therefore, activity D must finish on day 8. Now, activity G has an FS relationship with activity D, so activity G is dependent on the finish of activity D. That means G can start when D is completed on day 8. Since G has 6 days of duration, it will then be completed on day 14. This is the longest path in the diagram, so the Critical Path is C-D-G = 14 days.

Click on the activities with your mouse to select them.

### Which activities have 1 day of Float?

#### The Forward Pass and Backward Pass indicate that activities A & E have 1 day of Float. Activity D may appear to have float, but because it is on the Critical Path here, it does not. The FF-2 relationship with activity C means that D can start at any time as long as it finishes on day 8. Since it must finish on day 8, it does not have float.

Click on the activities with your mouse to select them.

### Which activities must finish no later than day 8?

#### Notice that there is an FF relationship between activities C & D with 2 days of lag as indicated by the FF-2. This means that activity D must finish 2 days before activity C finishes. Therefore, activity D must finish on day 8. Now, activity G has an FF relationship with activity D, so activity G is dependent on the finish of activity D. That means G can start when D is completed on day 8. Also, a standard Forward Pass and Backward pass indicates that activity E has 1 day of Float.

Click on the activities with your mouse to select them.

### Which activity has 1 day of Free Float?

#### Activity B has 1 day of Free Float, but 2 days of Total Float. Free Float is the amount of time an activity can be delayed without affecting the Early Start date of any successor activity, in this case activity E.

Click on the activity with your mouse to select it.

• 14 days
• 23 days
• 18 days
• 21 days

### The sponsor has requested that you compress the below schedule to complete it within 17 days, and has allocated additional funding to do this. Based on the crashing table shown, which of the following choices represents the best way to crash the schedule?

#### This question requires several steps and a lot of attention to detail! Identify all pathways on the PND ACEG=18 BCEG=17 ACF=13 BCF=12 BDEG=23 BDF=18  Notice that the critical path is BDEG which must be decreased by 6 days to meet the new sponsor deadline. There are also several other pathways that must be decreased to meet 17 days. Focusing on the critical path, notice that B, D, & G are all able to be crashed. Choose the cheapest options and crash B by 1 day for \$75, then D by 4 days for \$400, and then G by only 1 day for \$250. This will result in the following: ACEG=17 BCEG=15 ACF=13 BCF=11 BDEG=17 BDF=13      Note that although activity C is cheaper to crash than G, it will not decrease the Critical Path, and therefore is not a correct choice The end result is that you have crashed B by 1 day, D by 4 days, and G by 1 day for a total cost of \$725, but you have created 2 Critical Paths, so the project is more risky to complete!

• Crash B by 1 day, D by 4 days, and G by 1 day for a total cost of \$725 resulting in 2 critical pathways
• Crash B by 1 day, C by 1 day, D by 4 days, for a total cost of \$600 resulting in 3 critical pathways
• Crash B by 1 day, D by 4 days, and G by 1 day for a total cost of \$725 resulting in 2 critical pathways
• Crash B by 1 day, C by 1 day, D by 3 days, and G by 1 day for a total cost of \$550 resulting in 1 critical pathway