Critical Path Analysis

What is critical path analysis?

Management planning tool, improves the efficiency of the production processes by scheduling all tasks required to complete a project in the minimum amount of time possible

What do nodes show?

They show the start and finish time of each activity within a project

What is EST?

Earliest start time - shown in the top right hand side of the node, shows when a particular activity can begin

What is LFT?

Latest finish time - bottom right - deadline for a particular activity

What is total float time?

The amount of time that non-critical activities within the project can be delayed without affecting the deadline for completion of the project as a whole

What is free float?

Refers to amount of time that an activity can be delayed without affecting the EST of the next activity in the project.

How do you calculate total float time?

LFT - duration - EST

How do you calculate free float?

Free float = EST of next node - duration - EST of current node

What does the flexibility of float time allow you to do, must mention?

Flexibility of float time allows them to shift resources and skilled workers towards critical activities for any support or if any problems arise.

How to do EST and LFT working out which order?

EST - calculate first and always work from left to right

LFT - calculate after EST and always from right to left

What are the main benefits of CPA?

• Improves operational efficiency by identifying the critical path and float times, reducing lost time between activities

• Aids budgeting and cash flow management by showing when activities start and how long they last

• Helps with production planning and stock control – materials only need to be ordered in time for the earliest start time (EST), reducing storage costs

• Can be used for projects of any scale, from small to large-scale undertakings

What are the main limitations of CPA?

• Does not guarantee everything will go according to plan – internal and external factors (e.g., poor weather) can cause delays

• Does not guarantee it is the best project to pursue

• Can be highly complex for large projects

What are dummy activities?

Used to prevent illogical path followed in diagram, showed by dotted line

Learn dummy activity - how to do?

It happens when two things are dependent on same thing but not exactly same, example if D is preceded by C, then E is preceded by C and B they both share the C but don’t have C and B therefore needs a dummy activity for C