3.3.4 Critical Path Analysis

Question 1

What is critical path analysis?

Answer 1

The process of planning the sequence of activities in a project in order to identify the most efficient strategy for competition.

Question 2

What is the aim of critical path analysis?

Answer 2

The aim is to complete the project in the shortest time possible.

Question 3

What are the rules for constructing a critical path analysis?

Answer 3

1) work from left to right (add)
2) Focus on EST first
3) Take the highest value-adding the time taken
4) get to the end
5) Duplicate the number
6) Go back working right to left (minus)
7) Take the lowest value minusing time
8) Back to 0

Question 4

What is the critical path?

Answer 4

A path that shows tasks that must be prioritised

Question 5

What does it mean if a task is on the critical path?

Answer 5

the task must be prioritised

Question 6

What does it mean if a task is not on the critical path?

Answer 6

there is more flexibility around the task

Question 7

How do you indicate the critical path on a diagram?

Answer 7

using two parallel lines on the task line

Question 8

What do network diagrams/critical path analysis show?

Answer 8

1) The order of tasks
2) length of each stage
3) earliest date at which other stages start

Question 9

What is the EST?

Answer 9

Earliest start time

Question 10

What is the LFT?

Answer 10

Latest finish time

Question 11

What is the structure of a node in a critical path analysis?

Answer 11

The left half of the circle is the node containing the unique activity.
The top right section shows the EST
The bottom right section shows the LFT

Question 12

What do you do moving from left to right?

Answer 12

Add the duration to the EST (in the top right)

Question 13

What do you do moving from right to left?

Answer 13

Take the lowest value minusing the largest duration = LFTs.

Question 14

What is float time?

Answer 14

Flexibility you have to complete tasks not on the critical path

Question 15

How do you work out total float?

Answer 15

LFT - duration - EST

Question 16

What are the positives of using critical path analysis?

Answer 16

+ smooth operations, shorterns project length, good for problem-solving
- not useful for complex operations?, activity lines aren’t proportional

Question 17

What does float tell us?

Answer 17

Actual float tells us the degree of flexibility (hours/days..) to complete a particular task whilst still completing the project within the time frame.

Question 18

What are the uses of a critical path analysis?

Answer 18

• to estimate and minimise project time
• support project costing and evaluation
• plan and organise resources
• prioritise tasks
• help provide direction (improved motivation)

Question 19

What are the positives of using critical path analysis?

Answer 19

+ helps reduce risk and costs, + ensures accuracy during planning,
+ decision-making tool,
+ can shorten project length, spot where activities have some slack (float),
+ helps with coordination

Question 20

What are the negatives of using critical path analysis?

Answer 20

• reliability based off of accurate estimates and assumptions, CPA doesn’t guarantee success, too many activities may complicate the diagram, dependent on non-fixed variables e.g. weather/resources of capital