3.3.4 Critical Path Analysis

Question 1

What is critical path analysis?

Answer 1

• A project management tool that uses network analysis to plan complex & time-sensitive projects

Question 2

What does critical path analysis show?

Answer 2

• The order in which activities must be completed
• The longest path of project activities to the completion of the project
• The earliest & latest that each project activity can start & finish without delaying completion of the project as a whole
• Activities within a project that can be carried out simultaneously are identified
• The critical project activities which if delayed will cause the project as a whole to over-run
• The shortest time possible to complete the project

Question 3

What are the 3 elements when drawing critical path analysis?

Answer 3

Node- circle that represents a point in time where an activity is started or finished
- The node is split into three sections- The left half of the circle is the activity number
- The top right section shows the earliest start time (EST) that an activity can begin based on the completion of the previous activity
- The bottom right section shows the latest finish time (LFT) by which the previous activity must be completed

Activities- a process or task within a project that takes time
Activities are shown on the network diagram as a line which link nodes
A description of the activity or a letter representing the activity is usually shown above the line

Duration- the length of time it takes to complete an activity
duration is shown as a number of time units such as hours or days below the activity line

Question 4

What is float time?

Answer 4

• When there is a difference between the earliest start time and the latest finish time (spare time)
  Where float time is identified managers may:
• Transfer resources such as staff or machinery to more critical activities (other jobs)
  Allow extra time to complete tasks to improve quality or allow for creativity

Question 5

What are the limitations of critical path analysis?

Answer 5

• Very lengthy or complex projects involve a very large number of activities that have numerous dependencies–> Layers of supervision may be required to manage different groups of activities within the project
• Network analysis often relies on estimates and forecasts–>Significant research is required prior to the completion of network analysis
  Close & honest working relationships with suppliers are essential
• Network analysis does not guarantee the success of a project –>Project managers will need to be highly skilled & will need experience of working with complicated plans