What is UML and The Relationship between Patterns and UML

Definition :UML stands for Unified Modelling Language this is a technique which is used to illustrate or model software systems and help document the system needs as the project is being developed in an easy to understand concept. It is used in Object Oriented Programming .[1]

For other good definitions of UML see:
http://www.netclico.com/support%20glossary/u.html [2]
http://krypton.mnsu.edu/~spiral/eta/glosaary/indexGlossOOxml.html[3]
http://intentsoft.com/technology/glossary/html[4]

When developing software modelling or designing a system before coding and implementation is useful to the developers and users, it allows users to view the design and interaction of the system and make any changes before and during the development of the system. Developers can capture and document requirements needed to develop the system and enable flexible and robust systems to be developed .Designs also help developers to check on the progress and interaction of the system on the documentation and amend the requirements accordingly .[1]

Evolution of UML

1970`s – 1980 :The Object Oriented Languages emerged , developers used the variety of languages in analysis and design though there were several different outcomes for each project .In the late 80`s new languages continuously increased . [5]

Early 1990`s :Due to the problems faced by the developers of not being able to document or desing a system using one uniform Object Oriented Language a suggestion to merge the languages was put forward .[5]

1994 -1997: The decision was approved after the efforts of three men was published and feed back received , on improvements which could be made and incorporated .This helped the software development community to develop a standardised way of representing systems. After feedback and additional research the first version UML1.0 was established ,further research and responses from various companies gave rise to the revised UML 1.1 .The tool has improved continuously up to the present versions being used thus VERSION 1.5 UML and 2.0 UML.[5]

Why Developers Use UML

UML is a tool used to design systems before they are actually developed and coded , it helps software developers to plan for the duration of each task to be done and determine the milestones to be set and when they are to be achieved .The developers can also determine the effort needed in the development of a system thus the number of developers and their skills to complete the system.[2]

Usefulness of UML

· Describes the organisation and relationships of classes and objects in a system.
· When a plan or guide is followed when developing a system it is easy to follow and complete task by task and integrate them .
· High quality software systems are produced when there is an organised pattern to incorporate and follow .[2]
· UML analyses code that has been previously generated and converts it into UML models .
· Templates increase the flexibility in the software development hence the use of UML \diagrams help reduce maintenance cost and manage complexity .
· Standardise communication between (sw)developers .[2]
· It incorporates most of the Object Oriented Languages used to solve design problems hence produces a better solution than using one Object Oriented Language .[2]
· It can be used with any Object Oriented Language thus it is not language specific .

Diagrams Used in UML

Uses different diagrams to represent the same system thus Class , Ucase and Interactive diagrams though they vary in detail.

All these diagrams can be used to design and document a system though am are going to concentrate on Class diagrams .Class diagrams are used in relation with pasterns . The patterns that are used to develop software systems can be described in UML diagrams.
[3]

Notation and Key
Customer
CreditRating()
name: String
address: String
Class Name
Attributes
Operations

Class Diagram Example

Remind()
billForMonth ()
contanctName:String
CreditRating :String Operation
Credit Limit : Double

Cooperate Customer
dispatch()
close Properties
dataRecived : Date
isPrepaid :Boolean
number :string
price: money


Order
name: String
address : String
Creating Ratings
n Multiplicity
1

Customer
Personal customers
Creditcard #:Long integer

Reference:[3] Please Click Reference three to view diagrams

Class Diagrams : Show the relationships and collaboration of classes ,packages and
objects in a system.

Class diagrams describe the following perspective
1. Conceptual – abstract idea
2. Specification –a detailed description of performance
3. Implementation – something used to achieve a purpose

Reference:

1. Applying UML and Patterns : An Introduction to Object-Oriented Analysis and Design and Iterative Development (3rd Edition) (Hardcover
2. http://www.netclico.com/support%20glossary/u.html
3. http://atlas.kennesaw.edu/~dbraun/csis4650/A&D/UML_tutorial/history_of_uml.htm
4. http://krypton.mnsu.edu/~spiral/eta/glosaary/indexGlossOOxml.html
5. http://intentsoft.com/technology/glossary/html