6. Diagramming – an Introduction

In the early days of computers, diagramming didn't figure as an important topic in the design process. Further, the only pictorial method used was that of the flowchart. At that time, there was little distinction between programming and design (or, for that matter, between programmers and designers). The design and development process usually went as follows:

• Programmers thought about the problem to be solved
• They wrote lines of code to solve it
• The code was tested and modified until it was correct (or appeared to be so)
• The source code was released as the system documentation

Sometimes, in a token gesture to appease senior management (or the customer), a system flowchart was produced. Whether it represented what went on in the program is another matter.

In recent years, a revolution has taken place concerning the use of diagramming for software. Practically all modern software tools use diagrams as an...