The requirement phase is fundamental to all projects, big or small. Only when ALL the requirements for the network are known can more detailed design and planning take place.

Note that it is acceptable to have a requirement to be able to extend a network to new locations or to increase the size of an existing design, even if these details are not known, It ensures that the current design is capable of being extended as opposed to a network that has to be rebuilt from scratch to accommodate the additional elements.

The design phase can start once all the requirements have been identified. The output from the design stage will include the majority of the network documentation, a detailed design and a hardware component list.