Lesson 5: Object-Oriented Analysis and UML

Structured analysis models processes and data flows. Object-oriented analysis models the system as a set of objects, responsibilities, and interactions.

In object-oriented thinking, we focus on things such as users, records, transactions, services, and items handled by the system. These become classes or objects with attributes, operations (methods), and relationships to other classes.

Core object-oriented ideas include:

In Systems Analysis and Design, you do not need to code every class. What matters first is learning how to describe the problem domain in an organized, reusable way.

Example: in an appointment system, common classes may include Student, Appointment, ClinicStaff, and Prescription. Instead of thinking only about "Process Appointment," OO analysis asks:

• What does an Appointment know?
• What actions can an Appointment perform or trigger?
• Which class owns reschedule logic?
• What is the relationship between Student and Appointment?

This helps when the project will later be implemented using object-oriented programming.

A use case describes how an actor interacts with the system to achieve a goal.

Common parts of a use case: Actor, Goal, Precondition, Main flow, Alternative flow, Postcondition.

Example use case title: Submit Maintenance Request

• Actor: Student Resident
• Goal: report a maintenance issue
• Precondition: resident account is active
• Main flow: logs in → enters issue details → submits request → system records request
• Alternative flow: required field missing → system prompts correction
• Postcondition: request is saved and reference number is generated

Use case diagram basics

A use case diagram usually shows actors outside the system, use cases inside the system boundary, and relationships between them.

Sample use cases in a permit renewal system: Submit Renewal Application; Verify Documents; Assess Fees; Approve Application; View Application Status; Generate Daily Report.

Use case modeling is especially helpful because it translates stakeholder needs into system behavior without jumping too quickly into database or code details.