Software Requirements, 3rd Edition

Chapter 13. Specifying data requirements

Long ago I led a software project on which the three developers sometimes inadvertently used different variable names, lengths, and validation criteria for the same data item. In fact, I used different lengths for the variable that held the user’s name in two programs I wrote myself. Bad things can happen when you interconvert data of different lengths. You can overwrite other data, pick up stray pad characters at the end, have unterminated character strings, and even overwrite program code, eventually causing a crash. Bad things.

Our project suffered from the lack of a data dictionary—a shared repository that defines the meaning, composition, data type, length, format, and allowed values for data elements ...