Theme 3 Topic 9
Critical Path Analysis
Critical Path Analysis
Critical Path Analysis – using a network diagram to show
the tasks taken to complete a project in the minimum time
possible
Shows the sequence of activities required for the
project and the order in which they can be
completed
Its purpose is to plan projects in a way which
enables a project to be completed in the shortest
time possible
To Use the Technique a Manager Needs to Know:
What different tasks are involved
The length of time each task is expected to take
The order the tasks must be completed in – some can’t be started until another has finished
Features of a Critical Path Analysis:
Feature Explanation
Nodes and Node The circles represent a point in time at the start or end of an activity
Numbers Nodes are split into three
The left half of the node contains the number of the node – provides a unique
identity for each node
Earliest Start The right half of the node is split in two
Time (EST) The top segment shows the EST that an activity can commence
Depends on the completion of the previous activity
For the starting activity, the EST is always zero
Latest Finishing The bottom segment shows the LFT
Time (LFT) The latest time an activity can finish without delaying the overall project
Arrows Represent production activities, they must go left to right and begin and end
with a node
Below the line – a number which represents the length of time it takes to
complete that activity
Above the line – a letter or description of the activity that the line represents
The Critical Path Critical Path – the sequence of activities in a project that must be completed
within a designated time in order to prevent any delay in overall completion of
the project
Is shown by the symbol // over the arrow
Total Float Total Float – the amount of time that an activity can be delayed by without
delaying the entire project
Total Float for an Activity = LFT – Duration of Activity – EST
Key Points of a Critical Path Analysis:
Must start and end on a single node
No lines should cross each other
There is no limit on the number of activities that link to a single node
When drawing an activity, do not add the end node until you have looked to see which activity follows
It is helpful to draw networks with large circles and short lines – able to write figures in the nodes
Advantages of Critical Path Analysis Disadvantages of Critical Path Analysis
Critical Path Analysis
Critical Path Analysis
Critical Path Analysis – using a network diagram to show
the tasks taken to complete a project in the minimum time
possible
Shows the sequence of activities required for the
project and the order in which they can be
completed
Its purpose is to plan projects in a way which
enables a project to be completed in the shortest
time possible
To Use the Technique a Manager Needs to Know:
What different tasks are involved
The length of time each task is expected to take
The order the tasks must be completed in – some can’t be started until another has finished
Features of a Critical Path Analysis:
Feature Explanation
Nodes and Node The circles represent a point in time at the start or end of an activity
Numbers Nodes are split into three
The left half of the node contains the number of the node – provides a unique
identity for each node
Earliest Start The right half of the node is split in two
Time (EST) The top segment shows the EST that an activity can commence
Depends on the completion of the previous activity
For the starting activity, the EST is always zero
Latest Finishing The bottom segment shows the LFT
Time (LFT) The latest time an activity can finish without delaying the overall project
Arrows Represent production activities, they must go left to right and begin and end
with a node
Below the line – a number which represents the length of time it takes to
complete that activity
Above the line – a letter or description of the activity that the line represents
The Critical Path Critical Path – the sequence of activities in a project that must be completed
within a designated time in order to prevent any delay in overall completion of
the project
Is shown by the symbol // over the arrow
Total Float Total Float – the amount of time that an activity can be delayed by without
delaying the entire project
Total Float for an Activity = LFT – Duration of Activity – EST
Key Points of a Critical Path Analysis:
Must start and end on a single node
No lines should cross each other
There is no limit on the number of activities that link to a single node
When drawing an activity, do not add the end node until you have looked to see which activity follows
It is helpful to draw networks with large circles and short lines – able to write figures in the nodes
Advantages of Critical Path Analysis Disadvantages of Critical Path Analysis
