Architectural models use views to document a system's architecture from different perspectives. Views describe a system's structure and can be used to design and implement more detailed designs. There are four fundamental views in software architecture: the logical view shows key abstractions and objects, the process view shows system components and interactions, the development view decomposes software into components, and the physical view maps software to hardware. Together these views form the "4+1" model for documenting a system's architecture.

2.  Architectural Models of a Software
System can be used to focus discussion
about the software requirements.
 Architectures may be documented from
several different perspectives or views.
 A view describe the structure of a
system and Architectural views may be
used to document a design so that it
can be used as a basis for more detailed
design and implementation.

3.  Two Concepts are used in Architectural
views.
 What views or perspectives are useful for when
designing and documenting a systems
architecture?(VIEWS)
 What notations should be used for describing
architectural model?(Structure)

4.  Krutchen (1995), in his well known “4+1”
view model of software architecture suggest
that there should be the four fundamental
architecture views ,related using use cases or
scenarios, as follows:
 Logical views:
 Shows key abstractions in the system as object or object classes
 Relate the system requirements to entities.

5.  Process view:
 Shows how, at run-time, the system is composed of interacting processes.
 This view is useful for making judgments about non functional system
characteristics such as performance & availability.
 Development View:
 Shows how the software is decomposed for development
 Show the breakdown of software into components that are implemented
by a single developer or development team.
 Useful for managers and programmers.

6.  Physical View:
 Shows the system hardware and how software components are distributed
across the processors in the system.
 Useful for system engineers planning a system deployment.
Development
Logical View
View
Scenarios
Process View Physical view
“ 4+1” View Model