Describing Processes

This step is the logical description. We want to specify the inputs and outputs for the process and summarize the logic of the system 

In constructing a data dictionary, the analyst should consider the following points:

1. Each unique data flow in the DFD must have one data dictionary entry.

There is also a data dictionary entry for each data store and process

2. Definitions must be readily accessible by name.

3. There should be no redundancy or unnecessary definitions in the data definition. It must also be simple to make updates.

4. The procedure for writing definitions should be straight forward but specific. There should be only one way of defining words.

In summary a data dictionary is an integral component of the structured specification. Without a data dictionary, the DFD lacks rigor, and without the DFD, the data dictionary is of no use. Therefore, the correlation between the two is important.