Systems Analysis and Design

Modern Systems Analysis and Design
Third Edition

Jeffrey A. Hoffer Joey F. George Joseph S. Valacich

Chapter 8 Structuring System Requirements: Process Modeling
8.1 8.1

Copyright 2002 Prentice-Hall, Inc.

Learning Objectives
Understand the logical modeling of processes through studying data flow diagrams How to draw data flow diagrams using rules and guidelines How to decompose data flow diagrams into lower-level diagrams Balancing of data flow diagrams
8.2 8.2

Learning Objectives
Explain the differences among four types of DFDs: current physical, current logical, new physical and new logical Discuss the use of data flow diagrams as analysis tools Compare and contrast data flow diagrams with Oracle’s process modeling tool and with functional hierarchy diagrams Discuss process modeling for Internet applications
8.3 8.3

Process Modeling
Graphically represent the processes that capture, manipulate, store and distribute data between a system and its environment and among system components Data flow diagrams (DFD)
Graphically illustrate movement of data between external entities and the processes and data stores within a system
8.4 8.4

Process Modeling
Modeling a system’s process
Utilize information gathered during requirements determination Structure of the data is also modeled in addition to the processes

Deliverables and Outcomes
Set of coherent, interrelated data flow diagrams
8.5 8.5

Process Modeling
Deliverables and outcomes (continued)
Context data flow diagram (DFD)
Scope of system

DFDs of current system
Enables analysts to understand current system

DFDs of new logical system
Technology independent Show data flows, structure and functional requirements of new system
8.6 8.6

Process Modeling
Deliverables and outcomes (continued)
Project dictionary and CASE repository

8.7 8.7

Data Flow Diagramming Mechanics
Four symbols are used
See Figure 8-2 Two different standard sets can be used
DeMarco...