Software Architecture and UML Concepts

Modeling

• Models abstract a system at various levels of detail and precision
• Object-oriented methods address software modifiability, adaptation, and evolution

Unified Modeling Language (UML)

• A graphical language for describing models

Software Architectural Design

• Separates overall system structure and interconnections

Programming-in-the-Small

• Detailed design of individual components

Programming-in-the-Large

• Emphasizes component interconnections

Levels of Software Architecture

• High level: Decomposes the system into subsystems
• Low level: Decomposes subsystems into components

Multiple Views of Software Architecture

• Use case view: Input for developing new features
• Static view: Relationships and associations
• Dynamic state machine view: Internal control and sequencing
• Structural component view: Interconnected parts
• Dynamic concurrent view: Distributed modes communicating by messages
• Deployment view: Component assignment to hardware tools

Software

• A set of machine-readable instructions for specific functions

Software Types

• System software: e.g., Operating System
• Programming Tools & Language Translators
• Application Software:
  • Custom software
  • Generic software
  • Embedded software

Software Engineering

• Analytical approach to design, development, use, and maintenance

Ad hoc programming style

• Build & fix, code and fix

Software Crisis

• Projects failing to be reliable, on time, or within budget

Architecture

• Design of application software, protocols, and expansion means

System

• Collection of components, items, or equipment for a specific function

Architectural Design

• Used for defining complex systems for processors

Common Activities in Software Projects

• Requirement and Specification
  • Domain Analysis: Understanding the background
  • Defining the problem: Determining the precise problem to solve
  • Requirement Gathering: Obtaining all ideas
  • Requirement Analysis: Organizing the gathered information
  • Requirement Specification: Defining what and how the software should function
• Design
• Modeling
  • Use case modeling: Representing the sequence of actions performed
  • Structural modeling: Representing things as classes and objects
  • Dynamic & Behavioral Modeling: Modeling the activities that can be performed
• Programming: Translating design into programming language
• Quality Assurance: Reviews, inspections, and testing
• Deployment: Distributing and installing the software

Requirement Modeling

• Actors and use cases: Describing what the user expects from the system

Quality Attributes

• Correct
• Complete
• Unambiguous
• Consistent
• Verifiable
• Understandable by non-computer specialists
• Modifiable
• Traceable

Use Case Modeling

• Defines the functional requirements of the system in terms of actors and use cases

Use Case

• Defines the sequence of interactions between actors and the system
• Represented by ovals

Main Sequence

• Most common sequence of interactions between the actor and the system

Alternative Sequence

• Frequent interactions between the actor and the system

Scenario

• Each sequence through the use case

Association

• Communication between an actor and a use case
• Represented by lines

Actors

• An external user
• A role played in the application domain
• Represented by stick figures
• Primary actors: Initiate a use case
• Secondary actors: Participate in the sequence

System Boundary

• The scope or limits of the system

Software Requirement Specification

• A traceable document

Relationships

• Dependencies between use cases
• Include: Occurs when there is a common sequence
• Extend: Models alternative paths a use case might take

Activity Diagram

• Shows the flow of control and sequencing among activities
• Represents the sequence of activities, decisions, nodes, loops

Explore the fundamentals of software architecture, including various modeling levels and the use of Unified Modeling Language (UML). This quiz covers both small and large programming practices, as well as multiple views of software architecture. Test your knowledge on how systems are structured and interconnected.