Chapter 13 Logical Architecture

Logical Architecture Large-scale organization of classes Packages Subsystems Layers Tools - UML package diagrams

Layer Coarse grained Cohesive responsibility Strict or relaxed E.g. User Interface Strict or relaxed

Software Architecture Many definitions Key aspect: Large scale, big ideas Motivation Constraints Organization Patterns Responsibilities Connections

Design with Layers Organize layers using related responsibilities Collaboration and Coupling Layers Pattern Model view controller pattern

Why? Separation of concerns Encapsulate complexity Replaceable Reusable function Team organization

Domain layer vs. Application Layer Application layer organization Create domain object that encapsulate application logic (Domain Layer) Domain layer != Domain model However - many domain model concepts become domain layer classes

Terminology Tier - current usage: physical nodes Layers Partitions - parallel division of layers

SSD, System Operations, Layers When there is a UI layer: SSD shows operations to the UI Layer

Summary Separation into layers is a common first step In Architecture centric design, this flows from the software architecture