Editing Systems development life cycle (section)

=== Object-oriented analysis and design ===
[[Object-oriented analysis and design]] (OOAD) is the process of analyzing a problem domain to develop a conceptual [[model]] that can then be used to guide development. During the analysis phase, a programmer develops written requirements and a formal vision document via interviews with stakeholders.

The conceptual model that results from OOAD typically consists of [[use cases]], and [[class diagram|clas]]s and [[interaction diagram]]s. It may also include a [[user interface]] mock-up.

An output [[Artifact (software development)|artifact]] does not need to be completely defined to serve as input of object-oriented design; analysis and design may occur in parallel. In practice the results of one activity can feed the other in an iterative process.

Some typical input artifacts for OOAD:

* [[Conceptual model (computer science)|Conceptual model]]: A conceptual model is the result of object-oriented analysis. It captures concepts in the problem domain. The conceptual model is explicitly independent of implementation details.
* [[Use case]]s: A use case is a description of sequences of events that, taken together, complete a required task. Each use case provides [[Scenario (computing)|scenarios]] that convey how the system should interact with actors (users). Actors may be end users or other systems. Use cases may further elaborated using diagrams. Such diagrams identify the actor and the processes they perform.
* [[System Sequence Diagram]]: A System Sequence diagrams (SSD) is a picture that shows, for a particular use case, the events that actors generate, their order, including inter-system events.
* User interface document: Document that shows and describes the user interface.
* [[Data model]]: A data model describes how data elements relate to each other. The data model is created before the design phase. Object-oriented designs map directly from the data model. Relational designs are more involved.