It’s time for tea! - The Critical Path Analysis and how it works

It’s time for tea! - The Critical Path Analysis and how it works


An important part of your planning will be the critical path analysis. This is an effective tool to understand the key components, which  if delayed will have a direct impact on the success of delivering the project. (You can download the slides in PDF form to follow it visually)

What is a Critical Path Analysis? What does it look like? How do you use it? Considering how to make a  cup of tea might help.

  • Firstly, you will need to understand what the work breakdown and work flow will be.

  • Then you will need to assess the length of time it will take for each component to be ready, or delivered at each stage.

  • By adding up the time each component takes, you can determine the length of time the whole project will take.

  • Added factors can be, that some components are created in parallel, some take longer to complete, and some are dependent upon each other.

  • You have to work out all those dependencies to understand the critical points.

  • Once you do, then work back from the end of the project – adding up the longest part (in time) that the project will take. This gives you a basic critical path analysis.

The first picture below details the breakdown of the component parts to make a cup of tea.


The first level has two components – Ingredients and crockery.  Ingredients are made up of brewed tea, milk and sugar. Crockery is the ubiquitous tea cup, spoon and saucer. With this information, you are creating a root structure of the breakdown of the components for making a cup of tea.

Notice that at the 2nd level components break down to a 3rd level and 4th level of subcomponents, which need to be considered. Once you have created your components, you can plan the work flow which is the next stage. By checking each of these areas to see how they are dependent upon each other and the time they take, will provide the information you need to work out the critical path.

The critical path analysis is illustrated on the workflow diagram (see picture above - red arrows) with the additional components at the relevant stages. For example, the kettle can be considered an essential component; without it, no tea. You also need the water to be heated; without which, no tea. You need the tea leaves and finally you need the cup to hold the tea in.

The addition of cup, saucer, spoon, teapot, tea leaves, milk and sugar are the additional elements that make the cup of tea. These are the floating components which if delayed, will not delay the project overall. They are added on the critical path at the relevant time.



Identifying the critical path will provide information that will help you consider the risks.

For example, if you didn’t know there was a planned water stoppage in your street and your important client from abroad was arriving on the day the water was turned off, how would you make him his favourite drink in the UK?

Being aware of outside factors that could influence the project's successful delivery is a necessary part of risk analysis.

Another example being; When buying equipment from overseas the exchange rate might change from the time when you created the plan to the time you actually pay for the equipment resulting in an unexpected increase in costs.

Working backwards along the workflow from the end of the project you can calculate the overall duration of the project.

(Note: a useful FREE tool to download from the web to build your plan and find your critical path can be found at:


Released On 21st Oct 2015

  • FSB
  • Somerset Chamber of Commerce
  • Xero
  • cima
  • Automatic Enrolment
  • Sage Accountants' Club
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