Object-oriented systems
ü An
object-oriented system is composed of objects. The behavior of the system
results from the collaboration of those objects. Collaboration between objects
involves them sending messages to each other. Sending a message differs from
calling a function in that when a target object receives a message, it itself
decides what function to carry out to service that message. The same message
may be implemented by many different functions, the one selected depending on
the state of the target object.
ü The
implementation of "message sending" varies depending on the
architecture of the system being modeled, and the location of the objects being
communicated with.
Object-oriented analysis
ü Object-oriented
analysis (OOA) looks at the problem domain, with the aim of producing a
conceptual model of the information that exists in the area being analyzed.
Analysis models do not consider any implementation constraints that might
exist, such as concurrency, distribution, persistence, or how the system is to
be built. Implementation constraints are dealt during object-oriented design
(OOD). Analysis is done before the Design[citation
needed].
ü The
sources for the analysis can be a written requirements statement, a formal
vision document, interviews with stakeholders or other interested parties. A
system may be divided into multiple domains, representing different business,
technological, or other areas of interest, each of which are analyzed separately.
ü The
result of object-oriented analysis is a description of what the system is functionally required to do, in the form of a
conceptual model. That will typically be presented as a set of use cases, one
or more UML class diagrams, and a number of interaction diagrams. It may also
include some kind of user interface mock-up. The purpose of object oriented
analysis is to develop a model that describes computer software as it works to
satisfy a set of customer defined requirements.
Object-oriented design
Object-oriented
design (OOD) transforms the conceptual model produced in object-oriented
analysis to take account of the constraints imposed by the chosen architecture
and any non- functional – technological or environmental – constraints, such as
transaction throughput, response time, run-time platform, development
environment, or programming language.
ü The
concepts in the analysis model are mapped onto implementation classes and
interfaces. The result is a model of the solution domain, a detailed description
of how the system is to be built.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2024 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.