Software Architecture Design and the 4+1 View Model Overview

Software Architecture Design

Software architecture defines the structural elements, their externally visible properties, and relationships, providing a high‑level abstraction of a system’s structure, behavior, and attributes, and serving as a bridge between requirements analysis and detailed design.

4+1 View Model

The 4+1 view model consists of Logical View (supporting functional requirements), Development View (module organization), Process View (runtime characteristics such as performance and concurrency), Physical View (mapping to hardware and deployment), and Scenarios (use‑case abstractions) that tie the four views together.

Software Architecture Styles

Various architectural styles describe common organization patterns, including Data‑flow, Pipe‑and‑Filter, Call/Return, Object‑Oriented, Layered, Independent Component, Virtual Machine, Repository, Blackboard, and Closed‑Loop Control architectures, each with distinct characteristics and trade‑offs.

Layered C/S Architecture Evolution

Two‑tier client/server suffers from limited scalability, performance, and security; three‑tier C/S introduces Presentation, Business, and Persistence layers, improving modularity, maintainability, and security; three‑tier B/S further abstracts the client to a browser, enhancing deployment flexibility and openness.

MVC, MVP, and Extensions

MVC separates Model, View, and Controller to isolate UI logic; MVP refines this by preventing direct View‑Model interaction, using a Presenter; extensions include MVVM, Rich Internet Applications, distributed architectures, ANSI/IEEE 1471‑2000 viewpoint concepts, and the distinction between architectural styles and design patterns.