Critical path analysis

Question 1

Find LB of workers

Answer 1

= sum durations of activities / critical time

Round up, even if next digit is below 5

Question 2

If you are not given the early and late times of an activity network how can I find the criticial path?

Answer 2

Critical path is the longest to draw. Find the longest combination of arcs that get to the end. E.g. If most arc paths produce a path, 3 arcs long, the crtical path must be 4 arcs long.

Question 3

Why are dummy activities needed?

Answer 3

1. To show dependencies between activities
2. Every activity must be uniquely represented in terms of its events. There must be at most one activity between any two events. So dummy needed at the end of one of two the activities.

(Exam question came up on the 2nd point phrased in mark scheme as: 2 activities cannot start at the same event and event at the same event so a dummy is needed at the end of the activity)

Question 4

Early event time (choose the largest number)

Answer 4

the earliest time of arrival at the event allowing for the completion of all preceding activities

Question 5

Late event time (choose the smallest number)

Answer 5

the latest that the event can be left without extending the time needed for the project.

Question 6

Early event times uses forward/backward pass?

Answer 6

uses forward pass

Question 7

Late event times uses forward/backward pass?

Answer 7

uses backward pass

Question 8

The starting node aka

Answer 8

source node

Question 9

The finishing node aka

Answer 9

sink node

Question 10

If crtical activity times increase

Answer 10

the duration of entire project increases

Question 11

Critical path

Answer 11

is a path from the source node to sink node that entirely folllows critical activities. This is the longest path in the network

Question 12

Total float of an activity =

Answer 12

late event time - duration - early event time

Question 13

Gantt (cascade) chart

Answer 13

graphically represents the range of possible start and finish times for all activities on a single diagram.

Question 14

Gantt (cascade) chart and flexibilty in activities

Answer 14

no flexibility is illustrated for critical activities

total floats of each activity is represented by the range of movement of its rectangle on the chart

Question 15

Resource histogram

Answer 15

displays the number of workers needed for an activity