Learning Objectives Prepare and use data flow diagrams to understand, evaluate, and document information systems. Prepare and use flowcharts to understand, evaluate, and document information systems

4. • Prepare and use data flow diagrams to understand, evaluate, and
document information systems.
• Prepare and use flowcharts to understand, evaluate, and
document information systems

5. • Set of documents and models
Narratives, data flow models, flowcharts
• Describe who, what, why, when, and where of systems:
Input, process, storage, output, and controls

6. • Guideline and procedures for current employee to follow
• Training of new employees
• Review and evaluation of system effectiveness and controls
• Modification of existing system
• Proposed systems

7. • Represents a source of data or input into the system
or
• Represents a destination of data or output from the system

8. • Graphically describes the flow of data within a system
• Four basic elements
• Data source and destination
• Data flow
• Transformation process
• Data stores

10. • Movement of data among:
• Entities (sources or destinations)
• Processes
• Data stores
• Label should describe the information moving

11. • Represents the transformation of data

12. • A data store is a temporary or permanent repository of data.

13. • Data flow diagrams are subdivided into successively lower levels in order
to provide increasing amounts of detail.

14. Human
Resources
Departments
Employees
Bank
Govt.
Agencies
Manage-
ment
Payroll
Processing
System
• Context diagram for the S & S Payroll Processing System

15. • Understand the system
• Ignore certain aspects of the
system
• Determine system
boundaries
• Develop a context DFD
• Identify data flows
• Group data flows
• Number each process
• Identify transformational
processes
• Group transformational
processes
• Identify all data stores
• Identify all sources and
destinations
• Label all DFD elements
• Subdivide DFD

16. • Use symbols to logically depict transaction processing and the flow of
data through a system.
• Using a pictorial representation is easier to understand and explain versus
a detailed narrative.

17. • Flowcharting symbols can be divided into the following four categories:
1 Input/output symbols
2 Processing symbols
3 Storage symbols
4 Flow and miscellaneous symbols

20. • Document
• Illustrates the flow of documents through an organization
• Useful for analyzing internal control procedures
• System
• Logical representation of system inputs, processes, and outputs
• Useful in systems analysis and design
• Program
• Represent the logical sequence of program logic