Using work breakdown structures to estimate rough ideas
We’re in a state of conceiving ideas. There is only little time and the goal is not to start realization but to decide whether or not to start into a concept phase. Still the first questions are: How long would it take and how much will it cost?
Breaking it down will help you approach a possible answer.
So we have a rough idea possibly a giant project. No details are set yet and the scope is far from being fixed. How to answer the question?
Well, you can’t.
But you can divide the idea into smaller chunks and build your estimates on those. For example for a new website you will probably need a CMS and a delivery layer.
- Breaking down an idea into smaller parts that you can already identify has to follow a few rules.
- the 100% rule tells you that all parts you break down have to add up to the whole idea. Nothing must be left out and no two parts must overlap.
- don’t plan tasks but outcomes. At this stage don’t think about how do achieve things or who will have to do it.
- define a level of detail. In my case I wouldn’t get smaller than a three months worth part.
- all elements should be terminal in order to be estimated in terms of resource requirements, budget and duration.
In contrast to the definition taken from Wikipedia I would not recommend to define hierarchy levels as it will add more complexity than the vagueness at this stage justifies. Stay flat.
Now bring all these elements to a timeline. Don’t write any dates on it yet but place all elements in an order that resolves all dependencies. Which elements have to happen before other elements? Which elements could be done in parallel?
For each element you can now define how many people should work per element – and ideally what skills they require to have. Also define a budget you need to spend on other costs than resources like software licenses and infrastructure.
Lets assume that the smallest an element will take three months. Identify those elements that will probably take 6 or 9 months and look what it does to your timeline.
Be on the safe side and define figures that you think will be enough for any variation.
Now you can add up the figures. Add all the budget estimates for the overall budget. Add all the resources working in parallel while not mixing skills to come up with the resource requirement. Write down the duration of the whole project.
If you get the feeling that this project will not be approved because of your estimates try to identify earlier delivery points where you could be able to deliver a working solution that doesn’t include everything but enough to get started. Do not change the elements on your timeline.
Or if you do remember that every figure reduced will have to be another figure increased. Taking away resources will add to the duration and so does reducing budget estimates as they will lead to more work.