Buce Marjorie C

BSIS- OOA

SYSANAL

Book Review 11

Book: Systems Analysis and Design

Author: Julie Kendall and Kenneth Kendall

Reference No. QA 76.9 S88 K45 2002

Chapter 9

Quote: The system analysts needs to make use of the conceptual freedom afforded by data flow diagrams which graphically characterize data process and flow in a business process.

Data Flow approach to requirements determination

            In attempting to understand the information requirements of the users, the system analysts must conceptualize how data undergo and the output.

            Through the data flow diagram the system analysts put together a graphical representation of data process throughout the organization. The data flow approach the underlying system that it emphasizes. Using the combination of four symbols the system analysts create a pictorial depiction of process that will provide solid system documentation.

            Advantages of data flow approach

1. Freedom from committing to the technical implementation of the system too early.
2. Further understanding of the interrelatedness of systems and subsystems.
3. Communicating current system knowledge to users through data flow diagrams.
4. Analysis of a proposed system to determine to determine if the necessary data and processes have been defined.

The biggest advantage lies in the conceptual freedom found in the four symbols. Data flow approach serves as an exercise for the system analysts, enable them to understand the relatedness of systems and subsystems. It can also be used as a tool to interact with users.

            The last advantage of using data flow diagram is allowing analysts to describe each component in the diagram. Detecting and correcting errors and design flows of this nature in the earlier stages of the system development life cycle is far less costly than in the phases of programming, testing and implementation.

            In DFD, there is no distinction between manual and automated process. Manual processes are put together while automated processes paired with each other.