Structuring System
Process Requirements

• Upon completion of part I you will be able to:
– Understand and be able to explain the concepts related to the logical modeling process
– Understand and be able to draw data flow diagrams
– Understand and be able to decompose data flow diagrams into lower-level diagrams
– Understand and be able to balance higher-level and lowerlevel data flow diagrams
– Understand and be able to explain the concepts related to the differences between the four types of DFDs
– Understand and be able to explain the concepts related to
Oracle’s process modeling tool and with functional hierarchy diagrams

• Data Flow Diagrams
– Model data flow
– Data flow relationships
– Change processes
– Also called process models

• Overview
– Data flow diagram is common form
• Modeling a Systems Process for Structured Analysis
– Analysis team
– Organization of information
• Deliverables and outcomes
– Context diagram
– Diagrams of current system
– Logical data flow diagrams
– Data flow and functional requirements
– Entries of all objects in project dictionary

Diagramming
Mechanics

Diagramming
Mechanics

Diagramming
Mechanics
• Decomposition of DFDs
– From one system to multiple systems
– Functional decomposition
– Iterative process
– Finer and finer detail
– Primitive DFD
• Balancing DFDs
– Balancing inputs and outputs

• Current Physical
– People’s names
– Positions
• Current Logical
– Current system reduced to its essence
– Data and processes
• New Logical
– Additional functions
– Obsolete functions removed
• New Physical
– Automated and manual functions

Using Data Flow
Diagramming in Analysis
• DFD Guidelines
– Completeness
– Consistency
– Timing considerations
– The iterative nature of drawing DFDs
– Primitive DFDs

Using Data Flow
Diagramming in Analysis
• Using DFDs as Analysis Tools
– Gap analysis
– Redundant data flows
– Unused data
– Inefficiencies
– Current logical vs. new logical
• Using DFDs in Business Process Reengineering

• What is a Use Case
– Shows behaviors or functionality
– Set of sequences
– Use case
– Actor
• Use Case Diagram
– Depicted diagrammatically
• Written Use Cases

• Modeling a systems process for structured analysis
• Data flow diagram symbols
• Rules governing data flow diagramming
• Decomposition of DFDs
• Balancing DFDs
• The four types of DFDs
• DFD guidelines
• Using DFDs as analysis tools
• Use cases