The WBS contains all of the work in terms of the work to be completed!

Make sure that there is no overlap between to elements! Otherwise, cost calculation will be difficult and there will be miscommunication and work doubling.

If you write action oriented details in your WBS, there will be not enough or too much information. So it is better to present only expected results.

The questions when to stop dividing elements in smaller ones is important for the WBS. These to rules may help you:

1. One single action should not take more than 80 hours
2. A single action or a series of actions should not be longer then a single reporting period.

A working package at the activity level should:

1. be realistic
2. be atomic (not to be meaningfully divided)
3. produce a measurable outcome
4. a unique package, which can be outsourced

A elements should be coded correspondingly to the level of hierarch.

In your WBS, the lowest elements in a hierarchy are termal elements, wich are not subdivided. They will be used for the calculation of resource requirements.