I know that my understanding of the mechanics of design taught by this book has improved my development of new programs. This book should best be described as a tutorial on program development procedures, as everyone knows the easy part of writing a program is doing the code. It is much more difficult to design any non-trivial application than it is to write code. The three major steps in program development are analysis, design, and implementation. Steve Eckols presents the analysis of a new system from scratch and also the problem of capturing an existing manual system your customer is already using.
Analysis is done by constructing a data flow diagram.
The DFD is a drawing that shows how information comes into a system, what information goes out, and where and how the information is transformed in between. Construction of a complete DFD forces you to break a system down into manage-able parts, and doesn t let you loose track of the relationships. In the design phase you create content lists from the data flow diagrams you created in the analysis stage. You can now make system structure charts and design the database structures needed to support the system. The final part of the design is to write the program specifications using the DFD, content lists and the system structure charts.