The beginning of UML arrangement of unified Modeling Language

Introduction:

This period of time will be devoted to writing UML blog, due to the limited ability of individuals, if the blog errors in the place also asked the vast number of Bo friends to criticize. In order to better understand a process or thing, people usually build a model based on certain characteristics (shape, structure, or behavior) of the object being studied. A model is an abstraction of a system from a particular viewpoint, which can be a physical model, such as a building model, a teaching model, a toy, or an abstract figure or graphic model, such as a mathematical formula or a graph. The purpose of the model is not to replicate the real original, but to help people better understand the complex nature of things, the reaction process or the relationship between the various factors within the things. Let's go into the study of UML! First, let's introduce its history.

History:

The recognized object-oriented modeling language appeared in the middle of the 70 's. From 1989 to 1994, the number increased from less than 10 to more than 50 species. In many modeling languages, language creators strive to promote their own products, and in practice continue to improve. However, the users of OO methods do not understand the advantages and disadvantages of different modeling languages and the differences between each other, so it is difficult to choose the appropriate modeling language according to the application characteristics, so a "method war" broke out. In the 90, a number of new methods emerged, the most notable of which were Booch1993, oose and OMT-2. Booch is one of the earliest advocates of object-oriented approach, and he puts forward the concept of object-oriented software engineering. In 1991, he extended the previous work for ADA to the entire object-oriented design field. Booch1993 is more suitable for the design and construction of the system. Rumbaugh and others put forward the object-oriented modeling technology (OMT) method, adopted the concept of object-oriented, and introduced a variety of language-independent expressions. This method uses the object model, dynamic model, function model and use case model to complete the modeling of the whole system, the defined concepts and symbols can be used in the whole process of the analysis, design and implementation of software development, and the software developers do not have to transform concepts and symbols at different stages of the development process. The OMT-2 is particularly useful for analyzing and describing data-centric information systems.Jacobson introduced the Oose method in 1994, its greatest feature is the use case (Use-case), and introduces the concept of external role in the description of use case. The concept of use cases is an important weapon for accurately describing requirements, but the use case runs through the entire development process, including testing and validating the system. Oose is better suited to support business engineering and demand analysis. In addition, there is the Coad/yourdon method, known as Ooa/ood, which is one of the earliest object-oriented analysis and design methods. This method is simple and easy to learn, it is suitable for the beginners of object-oriented technology, but it is seldom used because of its limitation in processing ability.To sum up, first of all, in the face of a lot of modeling language, users because there is no ability to distinguish between different language differences, it is difficult to find a more suitable for their application characteristics of the language; second, many modeling languages are actually different; Thirdly, although the various modeling languages are mostly similar, there are still some subtle differences. The communication between users is greatly hindered. Therefore, objectively, it is necessary to carefully compare the advantages and disadvantages of different modeling languages and summarize the application of object-oriented technology based on the organization of joint design team, according to the application needs, take its essence, to its dross, differences, unified Modeling Language. In October 1994, Gradybooch and Jimrumbaugh began to devote themselves to this work. They first unified Booch93 and OMT-2, and in October 1995 released the first public version, called the Unified Approach UM0.8 (Unitiedmethod). In the fall of 1995, Oose founder Ivarjacobson joined in the work. Through the joint efforts of Booch, Rumbaugh and Jacobson, two new versions, namely UML0.9 and UML0.91, were released in June 1996 and October, and UM was renamed UML (unifiedmodelinglanguage). This is the development of UML and a step forward.in the 1996, some institutions have become increasingly clear about UML as their business strategy. UML developers have received a positive response from the public, and have initiated the establishment of the UML Member Association to improve, strengthen and promote the definition of UML work. Members at the time were Dec, HP, I-logix, Itellicorp, IBM, iconcomputing, Mcisystemhouse, Microsoft, Oracle, Rationalsoftware, TI, and Unisys. This body has played an important role in promoting the definition and release of UML1.0 (January 1997) and UML1.1 (November 17, 1997). Object-oriented technology and UML development process can be used to indicate that the emergence of standard modeling language is its important result. In the United States, as of October 1996, UML has received extensive support from industry, technology and application communities, and more than 700 companies have expressed support for UML as a modeling language. By the end of 1996, UML had steadily accounted for 85% of the object-oriented technology market, becoming the de facto industry standard for visual modeling languages. November 17, 1997, OMG adopted UML1.1 as a standard modeling language based on object-oriented technology. UML represents the development direction of the software development technology of object-oriented method, it has great market prospect, also has great economic value and national defense value. Describes the history of its development.

What is Unified Modeling Language:

UML incorporates the basic concepts of many previous modeling language methods, And these basic concepts are mostly the same as the basic concepts in other object-oriented technologies, so UML is bound to be a simple and consistent modeling language that is readily adopted by the users of these methods and other methods, and secondly, UML is not only a simple convergence of the above methods, but a broad consultation on the basis of these methods, Set the length of the family, after several modifications and completed, UML extends the existing methods of application scope; Thirdly, UML is the standard modeling language, not the standard development process. Although the application of UML must take the development process of the system as the background, it is necessary to adopt different development process because of different organization and different application fields. uml as a modeling language, the definition of UML includes two parts of UML semantics and UML notation. (1) UML Semantic description is based on UML's exact meta-model definition. The meta-model provides simple, consistent, and generic definitions for all elements of UML in syntax and semantics, enabling developers to achieve semantic consistency and eliminate the impact of the best expression methods that vary from person to person. In addition, UML supports extended definitions of meta-models. (2) UML notation defines the representation of UML notation, Using these graphical symbols and text syntax for developers or development tools provides the standard for system modeling. These graphical symbols and literals express the application-level model, which is semantically an instance of the UML Metamodel. uml precise meta-model definitions and simple and uniform symbolic representations have also become a reason for their widespread adoption.

The main content of UML:

It shows the classification of UML diagrams, and also tells the UML Diagram modeling tool to be divided into two categories, a total of 13 kinds of graphs.

The first class is the structure diagram. In the structure diagram, UML2.0 has 6 graphical modeling tools: Class Diagram, Component diagram, object graph, composite structure diagram, deployment diagram, and package diagram.

The second category is the behavior diagram. In the behavior diagram, UML2.0 has 7 time tools: Activity diagram, use case diagram, state diagram, and 4 interaction graphs-sequence diagram, communication diagram, interaction synthesis Diagram and time configuration diagram.

Application areas of UML:

The goal of UML is to describe any type of system in object-oriented graph, which has a wide range of applications. One of the most common is the model of a software system, but it can also be used to describe systems in non-software areas, such as mechanical systems, enterprise organizations or business processes, as well as information systems dealing with complex data, industrial systems or industrial processes with real-time requirements. In summary, UML is a common standard modeling language that can model any system that has static structure and dynamic behavior.In addition, UML is suitable for different stages of system development from requirements specification to test after system completion.in the requirements analysis phase, you can use use cases to capture user requirements. Use case modeling to describe external roles that are of interest to the system and their functional requirements for systems (use cases). The analysis phase focuses on the main concepts in the problem domain (such as abstractions, classes, objects, etc.) and mechanisms, needs to identify these classes and their relationships with each other, and describes them with UML class diagrams. To implement use cases, the classes need to collaborate, which can be described using a UML dynamic model. In the analysis phase, only the object of the problem domain (the real-world concept) is modeled, regardless of the class that defines the technical details in the software system (such as classes that handle issues such as user interfaces, databases, communications, and parallelism). These technical details are introduced in the design phase, so the design phase provides a more detailed specification for the construction phase. Programming (construction) is a separate phase whose task is to translate classes from the design phase into actual code in an object-oriented programming language. When building analysis and design models with UML, it is necessary to avoid considering transforming the model into a specific programming language. Because in the early stages, the model is merely a tool to understand and analyze the structure of the system, premature consideration of the coding problem is very detrimental to the establishment of a simple and correct model. the UML model can also be used as a basis for the testing phase. Systems typically require unit testing, integration testing, system testing, and acceptance testing. Different test teams use different UML diagrams as a test basis: Unit tests use class diagrams and class specifications, integration tests use part diagrams and collaboration diagrams, system tests use use case diagrams to verify the behavior of the system, and acceptance tests are performed by the user to verify that the results of the system tests meet the requirements identified during the analysis phase. In short, the standard modeling language UML applies to object-oriented technology to describe any type of system, and is suitable for different stages of system development, from requirements specification to test and maintenance after the system is completed.

Resources:

1. UML Baidu Encyclopedia
2. Unified Modeling Language UML (second edition) Yuan Tao
3. Unified Modeling Language (UML) reference manual

The beginning of UML arrangement of unified Modeling Language