Structured Analysis vs Object-Oriented Analysis
System analysis can be performed using different methodologies. Structured analysis is the traditional approach that models data and processes separately. Object-oriented analysis (OOA) models the system as interacting objects that combine data and behavior. Understanding both approaches is essential for modern analysts.
Structured Analysis Overview
Structured analysis views a system as a collection of processes that transform data. It uses separate models for data and processes.
Key Tools:
- Data Flow Diagrams (DFDs) -- model processes and data flows
- Entity Relationship Diagrams (ERDs) -- model data structures
- Data Dictionary -- document data elements
- Process Specifications -- describe process logic
Philosophy:
"A system is a set of processes that transform data"Object-Oriented Analysis Overview
OOA views a system as a collection of objects that interact with each other. Objects encapsulate both data (attributes) and behavior (methods) into unified entities.
Key Tools:
- Use Case Diagrams -- model system functionality
- Class Diagrams -- model objects and their relationships
- Sequence Diagrams -- model object interactions over time
- State Diagrams -- model object state changes
Philosophy:
"A system is a collection of interacting objects"Comparison Table
| Aspect | Structured Analysis | Object-Oriented Analysis |
|---|---|---|
| View | Data + Processes (separate) | Objects (data + behavior combined) |
| Modeling | DFDs, ERDs | Class diagrams, use cases |
| Decomposition | Functional decomposition | Object decomposition |
| Best for | Data-intensive, batch systems | Interactive, complex systems |
| Code mapping | Procedural code | Object-oriented code |
When to Use Which Approach
- Structured Analysis: Legacy system replacement, data processing systems, projects with clear sequential workflows
- OOA: GUI-based applications, real-time systems, complex business domains with many interacting entities
- Hybrid: Many organizations use a combination, especially when integrating legacy and modern systems
Evolution of Analysis Methods
The shift from structured to object-oriented analysis mirrors the shift from procedural to object-oriented programming. While OOA is more prevalent today, structured analysis remains valuable and is still used in specific contexts. Modern analysts should be proficient in both approaches.
Summary
Both structured and object-oriented analysis have their place in modern system development. The choice depends on the project's nature, the team's expertise, and the organization's technology strategy. Understanding both approaches gives analysts flexibility to choose the best tool for each situation.