Software Architecture

Software Architecture

1. The notion of architecture

   • Architecture in the discipline of buildings
     • buildings like programs must fulfill a function
       • The main function of the systems is an important factor while in a building the main function determines its structure
   • Architecture in the discipline of computer hardware.
     • In the study of computer hardware, computer scientists have developed a number Of the computer architectures as successful designs of computer systems. the basic ideas of design are
       • Stored program, Sequential execution
     • The primary function of the CPU is to execute the instructions fetched from the main memory. The instruction tells the CPU to perform one of its basic
   • The general notion of architecture
     • common characteristics of the notion
       • 1.Architecture is an abstract model
         • 2.Architecture is a structural model
           • 3.Architecture is a model with a certain engineering purpose

2. The notion of software architecture

   • Prescriptive models
     • Software Architecture = {Elements, Form, Rationale} -----> defined the principal software architecture.
       • there are three different kinds of architecture
         • Data elements.
         • Connecting elements.
         • Relationships
         • Properties
         • Weight
   • Descriptive models
     • considers architecture as a description of the high level structure in terms of architectural
       • their model of software architecture only consists of two parts
         • Components
         • Connectors
   • Multiple view models
     • The view proposed by Shawn and Garlan is not unique, that is, a system must have multiple views in time of execution
       • Keys Concepts
         • Components
         • Externally visible properties
         • Structures
   • The roles of architecture in software design
     • Important reasons why software architecture is important
       • Communication among stakeholders
         • Manifestation of early design decisions
       • Representation of transferable abstraction of a system

3. Software architectural style

   • Introductory examples
     • Audio transcription system
     • Projection keyboard
   • The notion of software architectural style
     • both systems can handle continuous flows
     • The system can be easily changed simply by replacing certain components