scheduling

Question 1

what is the physical limit of an activity

Answer 1

max amount of days an activity can be shortened

Question 2

what is the logical limit of an activity

Answer 2

days an activity can be shortened before creating another critical path

Question 3

4 types of logical relationships

Answer 3

start-start
start-finish
finish-finish
finish-start

default is finish-start

Question 4

Describe what “Top Down Planning” means

Answer 4

Starting with an overall view of the project and then breaking it down into it’s major components. Then breaking those components down into sub elements until a sufficient level of detail is attained. result is a work break down strucutre

Question 5

Describe what “start to finish/beginning to end planning” means

Answer 5

begin with mobilization and proceed step by step through the project to completion.

although intuitive, has drawbacks: Some projects are so complex that it is difficult to visualize the best way to sequence the construction operations. Team members may not agree on the level of detail required. There is also a tendency to use greater detail in the earlier stages of the job and to generalize in the latter stages. The planning team may leave out entire groups of vital operations and hence drastically underestimate the time required for completion of the project. for this reason top down is preffered in industry

Question 6

what is TF (total float)

Answer 6

the maximum that the ES of an activity can be delayed without changing the overall project duration

for a given activity: TF = LS-ES or LF - EF

if you use up an activites TF that activity becomes critical. will create additional CP

TF for crit activities = 0

TF=FF+IF

Question 7

What is FF (free float)

Answer 7

the maximum that the ES of an activity can be delayed w/o changing the ES of ANY immediatly following activity

Question 8

what is IF (interfering float)

Answer 8

the change in ES of ANY following activity if the TF is utilized on the precceding activity

Question 9

what does CPM stand for

Answer 9

critical path method

Question 10

what are the 2 cpm diagrams

Answer 10

AOA and AON

Question 11

what determines project duration

Answer 11

the critical path activites

Question 12

what is early start (es)

Answer 12

latest EF of all IPA’s

Question 13

what is late finish (lf)

Answer 13

earliest late start of succeding activites

Question 14

what is late start

Answer 14

late finish - duration

Question 15

what is early finish

Answer 15

ES + dur

Question 16

what is critical path

Answer 16

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

Question 17

why would a contractor want to crash a schedule

Answer 17

to start another job sooner / the project is behind schedule and needs to get back on track

Question 18

why would an owner want to crash a schedule

Answer 18

to complete the job sooner and/or generate revenue sooner

Question 19

what kind of float would you give to superintendant

Answer 19

free float, becuase they are free to use up an activites free float with no impact to other activities if needed. Using total floats would affect others work schedules by delaying their ES

Question 20

what are the steps for crashing?

Answer 20

1. do a forward and backward pass to determine initial project duration and critical path(s)
2. determine the direct cost, indirect cost, and total cost
3. determine the next longest path
4. determine the activity on each critical path with the lowest cost slope
5. determine the physical limits for those activies and the logical limit, and shorten each of those activities by the lowest of the limits (1 logical limit, and a physical limit for each activity being crashed)
6. recalculate direct, indirect, and total costs with the new project duration
7. do another forward and backward pass
8. repeat steps 3-7 until the duration cannot be lowered any more
9. plot a graph of cost vs. duration, and find the lowest cost to determine the optimum schedule

Question 21

which activity to start for resource levelling

Answer 21

activites with earliest last start

Question 22

things to remember for resource levelling

Answer 22

• start at time 0
• mark off activities on diagram when they finish
• make sure im using as much resources as possible
• rule is to start activites with EARLIEST LATE START
• use amap resources