Research Review on Basic Principles of Unified Modelling Language

Transcription

1 Research Review on Basic Principles of Unified Modelling Language Agha Salman Haider Sr Lecturer, Jazan University, Saudi Arabia Abstract This paper presents review of concepts, ideas and the introduction to the use Unified Modelling Language (UML) as being a typical notation regarding real-world objects with developing object-oriented layout technique pertaining to computer applications. The Unified Modelling Language (UML) is among the most widely known along with utilized notation intended for object-oriented investigation along with design. It does not take consequence of the particular merger regarding various first advantages to be able to objectoriented approaches. UML doesn't identify effectively concerning kinds along with instructional classes notation ally, yet we could increase the particular stereotype «type» towards class symbol to demonstrate the particular big difference. Stereotypes tend to be tags which might be added to things to be able to classify all of them in numerous techniques. The UML is a tool for specifying software systems that include standardized diagrams to define illustrate and visually map or model a software system's design and structure. Keywords UML, Merger, Stereotype INTRODUCTION Object-oriented modelling different languages made an appearance sometime between the the middle of 1970s and also the later 1980s while methodologists, confronted with a whole new style associated with objectoriented selection different languages along with increasingly intricate software, began to research alternate ways to analysis along with pattern. The amount of object-oriented techniques elevated through lower than 10 for you to more than 50 throughout the time between 1989 along with Agha Salman Haider Page 30

2 Many people refer to this Specific Modelling Words while UML. This UML is surely an international sector normal graphic notation with regard to conveying software analysis along with styles. Every time a standardized notation is utilized, there is tiny bedroom with regard to misinterpretation along with ambiguity. Therefore, standardization offers efficient communication along with contributes to a lot fewer glitches a result of uncertainty. This Ough throughout UML stands for single considering that the UML can be a unification along with standardization associated with before modelling notations associated with Booch, Rumbaugh, Jacobson, Mellor, Shlaer, Coad, along with Wirf-Brock, a few. The actual UML the majority of carefully reflects the actual put together work connected with Rumbaugh, Jacobson, along with Booch often referred to as the actual about three amigos. The actual UML have been accepted as a standard by the Object Management Group (OMG). The actual OMG can be a non-profit organization together with in relation to seven-hundred people in which pieces criteria intended for distributed object oriented computing. Step one in acquiring a great object-oriented pattern strategy pertaining to computer applications along with pertaining to database system can be using UML (Unified Modeling Language) like a typical notation for your modeling regarding real-world objects. Software systems designers as well as architects get many options pertaining to supplying reliable, adaptable as well as efficient item perseverance pertaining to computer applications purposes as well as databases methods. They are able to select from Object-Oriented, Object- Relational hybrids, 100 % pure Relational as well as custom solutions based on available as well as proprietary file formats. UML is considered an industry standard modeling language with a rich graphical notation, and comprehensive set of diagrams and elements. It is used to specify, visualize, modify, construct and document the artifacts of an object-oriented software-intensive system under development. Purpose of Modelling: According to Booch, modeling achieves four aims: 1. Models help you to visualize a system, as you want it to be. A model helps the software team communicate the vision for the system being developed. It is difficult for a software team to have a unified vision of a system that is described only in specification and requirement documents. Models bring about understanding of the system. Agha Salman Haider Page 31

3 2. Models permit you to specify the structure of behavior of a system. A model allows how to document system behavior and structure before coding the system. 3. Models give a template that guides you in constructing a system. A model is an invaluable tool during construction. It serves as a road map for a developer. Have you experienced a situation where a developer coded incorrect behavior because he or she was confused over the wording in a requirements document? Modeling helps alleviate that situation. 4. Models document the decisions you ve made. Models are valuable tools in the long term because they give hard information on design decisions. You don t need to rely on someone s memory. The four basic principles of modeling are derived from this history. 1. The models you create profoundly influence how a problem is attacked and how a solution is shaped. 2. Every model may be expressed at different levels of precision. 3. The best models are connected to reality. 4. No single model is sufficient. Every non-trivial system is best approached through a small set of nearly independent models. Object Orientation Object Orientation is a bottom up approach of solving real world problem where individual objects are combined or assembled to provide the solutions of the underlying problem. In object orientation instead of writing subroutines the programmer can assemble the object and generate the desired result. Basic Principles of Object Orientation There are four basic principles of object orientation. They are: Abstraction Encapsulation Modularity Hierarchy Abstraction: The following are examples of abstraction. Agha Salman Haider Page 32

4 A student is a person enrolled in classes at the university. A professor is a person teaching classes at the university. A course is a class offered by the university. A course offering is a specific offering for a course, including days of the week and times. Encapsulation: The important thing to encapsulation is surely an object s information software. The item software means that all conversation while using the subject takes place by way of a set of predefined businesses. Files into the subject are merely obtainable with the object s businesses. Zero various other subjects can easily achieve within the subject and adjust its capability prices. For example, Professor Clark needs to have her maximum course load increased from three classes to four classes per semester. Another object will make a request to Professor Clark to set the maximum course load to four. The attribute, MaxLoad, is then changed by the SetMaxLoad() operation. Encapsulation works on this illustration considering that the requiring subject doesn't need for you to understand how to alter the most load insert. Down the road, how many issues which are helpful to outline the most load insert could possibly be increased, although that doesn't affect the actual requiring subject. Modularity: Often, the system under development is too complex to understand. To further understanding, the system is broken into smaller blocks that are each maintained independently. Breaking down a system in this way is called modularity. It is critical for understanding a complex system. For example, the system under development is a Course Registration system. The system itself is too large and abstract to allow an understanding of the details. Therefore, the development team broke this system into three modular systems, each independent of the others. The Billing System Course Catalog System Agha Salman Haider Page 33

5 Student Management System Hierarchy : Any ranking or ordering of abstractions into a tree-like structure. Kinds: Aggregation hierarchy, class hierarchy, containment hierarchy, inheritance hierarchy, partition hierarchy, specialization hierarchy, type hierarchy. (Dictionary of Object Technology, Firesmith, Eykholt, 1995) Hierarchy organizes items in a particular order or rank (for example, complexity and responsibility). This organization is dependent on perspective. Using a hierarchy to describe differences or variations of a particular concept provides for more descriptive and cohesive abstractions and a better allocation of responsibility. In any one system, there may be multiple abstraction hierarchies (for example, a financial application may have different types of customers and accounts). Hierarchy is not an organizational chart or a functional decomposition. Hierarchy is a taxonomic organization. The use of hierarchy makes it easy to recognize similarities and differences. For example, botany organizes plants into families. Chemistry organizes elements in a periodic table. Conclusion: As per our review the main aim of UML is to specify, visualize, modify, construct and document the artifacts of an object-oriented software-intensive system under development. UML helps in visualize the system, specify the structure of system and in constructing of system. It helps in model the document for decision. In our next paper we will discuss the UML for Database system. REFERENCES. Code Complete - A Practical Handbook of Software Construction, McConnell, S., Microsoft Press, Dynamics of Software Development, McCarthy, J., Microsoft Press, The Mythical Man-Month, Brooks, F.P., Jr., Addison-Wesley, Best of Booch: Designing Strategies, Booch, G., and Eykholt, E., editor, SIGS Books & Multimedia, Agha Salman Haider Page 34

6 Designing Object-Oriented Software, Wiener, L., Wilkerson, B., and Wirfs-Brock, R., Prentice Hall, Dictionary of Object Technology, Eykholt, E., and Firesmith, D., SIGS Books, Object-Oriented Analysis and Design with Applications, Booch, G., Benjamin/ Cummings, Object Oriented Design Heuristics, Riel, Arthur J., Addison-Wesley, Object-Oriented Modeling and Design, Rumbaugh, J., and others, Prentice Hall, Object-Oriented Software Development, Lorenz, M., Prentice Hall, Object-Oriented Software Engineering, Jacobson, I., and others, Addison-Wesley, OMT Insights: Perspectives on Modeling, Rumbaugh, J., Journal of Object- Oriented Programming, SIGS Books & Multimedia, The Rational Unified Process, Philippe Krutchen, Addison Wesley Longman, Inc., Using CRC Cards, Wilkinson, N., SIGS Books, The Object Primer: Agile Model-Driven Development with UML 2.0, Scott Ambler, Cambridge University Press, Real-Time UML: Developing Efficient Objects For Embedded Systems, Douglas, B. Powel, Addison Wesley Longman, Inc., UML in a Nutshell: A Desktop Quick Reference, Si Alhir, Sinan, O Reilly & Associates, Inc., The Unified Modeling Language User Guide, Booch, G. and others, Addison-Wesley, The Unified Modeling Language Reference Manual Second Edition, James Rumbaugh, Ivar Jacobson, Grady Booch, Addison-Wesley, UML Bible, Pender, T., Wiley Publishing, Inc., UML Distilled Third Edition, Fowler, Martin, Addison Wesley Longman Inc., UML Toolkit, Eriksson, H., Penker, M., Lyons, B., and Fado, D., Wiley Publishing, Inc., Agha Salman Haider Page 35

7 Unified Method for Object-Oriented Development (documentation set, v0.8), Booch, G. and Rumbaugh, J., Rational Software Corp., Agha Salman Haider Page 36