Structuring System Requirements: Process Modeling
Chapter Overview
Chapter 8 introduces students to several process modeling techniques for representing business processes. Although this chapter focuses primarily on data flow diagramming, brief overviews of functional hierarchy modeling and Oracle’s process modeler are given.
After a brief introduction to process modeling, data flow diagramming techniques are introduced in a section called “Data Flow Diagramming Mechanics.” This section demonstrates the basic DFD symbols, definitions, and rules. The authors use the Gane and Sarson symbol set throughout the book, and these symbols are explained in this section. Hoosier Burger, the food ordering system first mentioned in Chapter 2, is used to illustrate basic data flow diagramming concepts. This section also includes explanations of decomposition and balancing.
Chapter 8’s third major section introduces four different types of DFDs: current physical, current logical, new logical, and new physical. Hoosier Burger’s inventory control system (which is manual) is used to illustrate the first three types of DFDs. Current practice in using DFDs indicates that very little time should be spent on the current physical DFD.
The fourth major section in this chapter, “Using Data Flow Diagramming in the Analysis Process,” introduces guidelines for drawing and using DFDs. This is different from the mechanical rules presented earlier. Topics include completeness, consistency, timing, iterative development, primitive DFDs, and analyzing DFDs for system inefficiencies and discrepancies among DFDs that are supposed to be modeling the same system. A Hoosier Burger example helps illustrate these guidelines.
The “Oracle’s Process Modeler and Functional Hierarchy Diagrams” section introduces students to two other process modeling tools. These tools are Oracle Designer’s process modeler and functional hierarchy modeling, a tool found in several