Scheduling

Question 1

What does CPM stand for?

Answer 1

Critical Path Method

Question 2

What are the 2 CPM diagrams?

Answer 2

Activity on Arrow and Activity on Node (AOA and AON)

Question 3

What determines the project duration?

Answer 3

The critical path activities

Question 4

What is Early Start (ES)?

Answer 4

Latest EF (early finish) of all IPA’s

Question 5

What is Early Finish (EF)?

Answer 5

Early Start + Duration

Question 6

What is Late Finish (LF)?

Answer 6

Earliest late start of succeeding activities

Question 7

What is Late Start (LS)?

Answer 7

Late Finish - Duration

Question 8

What is Total Float (TF)?

Answer 8

The time an activity can be delayed without affecting project completion (LS - ES)

Question 9

What is Free Float (FF)?

Answer 9

The time an activity may be delayed without affecting the early start of any of the next immediate activities

Question 10

What is Critical Path (CP)?

Answer 10

The longest interconnected path through the network which has a length equal to the project duration

Question 11

What is the procedure for network calculations?

Answer 11

1) Do and forward pass and calculate all ES’s and EF’s
2) Do a backwards pass and calculate all LF’s and LS’s
3) Calculate floats
4) Determine critical path

Question 12

For resource levelling, which activities are proceeded with first and given the most importance?

Answer 12

The activity with the earliest late start

Question 13

What is Interfering Float (IF)?

Answer 13

The amount of time an activity can be delayed or extended from its ES without delaying the total float (TF)

Question 14

What are the values for TF, FF, IF for critical path activities?

Answer 14

0

Question 15

What does a negative total float (TF) represent?

Answer 15

Means you have to make up (save) that duration

For example if activity B has a TF of -3 then activity B must be cut short by 3 days in order to not disrupt the project completion date

Question 16

What is an example of a non-network type of scheduling?

Answer 16

Gantt Chart

Question 17

Why would a contractor want to crash a schedule?

Answer 17

To save time on a project
To save money on a project
To make up time on a project

Question 18

What are the steps involved in schedule crashing?

Answer 18

1) Do a forwards and backwards pass
2) Identify critical path
3) Identify critical activities
4) Identify next longest path
5) Identify the activity with the lowest cost slope in critical path
6) Determine the physical limit and calculate the logical limit
7) Crash the activity with the lowest cost slope by the lower of the logical or physical limit
8) Recalculate the forward and backwards pass
9) Calculate indirect costs
10) Calculate total direct cost

Question 19

What is direct cost?

Answer 19

Any cost that can be associated with a discrete physical part of a construction project

Question 20

What is indirect cost?

Answer 20

Any cost that cannot be associated with a discrete physical part of a construction project

Question 21

What is the physical limit?

Answer 21

The max number of days you can reduce an activity without making it impossible to complete

Question 22

What is the logical limit?

Answer 22

The max number of days you can reduce an activity before creating another critical path

Question 23

What is the formula for cost slope?

Answer 23

(crash cost - direct cost)/crash duration