軟件開發(fā)設(shè)計(jì)外文翻譯文獻(xiàn)本科畢業(yè)論文

1、外文資料原文Software Development Concepts and Design MethodologiesDuring the 1960s, mainframes and higher level programming languages were applied to many problems including human resource systems, reservation systems, and man

2、ufacturing systems. Computers and software were seen as the cure all for many business issues were sometimes applied blindly. Systems sometimes failed to solve the problem for which they were designed for many reasons in

3、cluding:?Inability to sufficiently understand complex problems?Not sufficiently taking into account end-user needs, the organizational environment, and performance tradeoffs?Inability to accurately estimate development t

4、ime and operational costs?Lack of framework for consistent and regular customer communicationsAt this time, the concept of structured programming, top-down design, stepwise refinement，and modularity emerged. Structure

5、d programming is still the most dominant approach to software engineering and is still evolving. These failures led to the concept of “software engineering“ based upon the idea that an engineering-like discipline c

6、ould be applied to software design and development.Software design is a process where the software designer applies techniques and principles to produce a conceptual model that describes and defines a solution to a probl

7、em. In the beginning, this design process has not been well structured and the model does not always accurately represent the problem of software development. However, design methodologies have been evolving to ac

8、commodate changes in technology coupled with our increased understanding of development processes.Whereas early design methods addressed specific aspects of the development process, current methods attempt to add

9、ress the entire scope of software development. Software design methods are often classified in reference to the period in which they were introduced and the problems at that time. Driven by c

10、oding and testing problems, 3implementation, testing, and maintenance. This thought process is inadequate for today's complex information systems. As the demand for software is growing much fa

11、ster than the number of developers, adhering to conventional techniques such as the waterfall method requires too much time, too many people, and is difficult to manage. Hence, many new software development t

12、echnologies have arisen. Newly developed practices and models do not attempt to separate phases of software development, such as specification and implementation, but instead focus on the concept of program transformatio

13、n through stepwise refinement and iteration.1 、Object-Oriented TechnologyObject-Oriented (O-O) software design technology is fundamentally different from the traditional methods described above. With traditional methods,

14、 each module is recognized a major step in the overall process and the process goes from one step to the next. On the other hand, O-O design is structured around a model of objects and the functions they perform.O-O prog

15、ramming can be traced to the simulation language SIMULA, a high level language developed in the late 60's that introduced object classes as a method to encapsulate data. Later, in the 1970s, Smalltalk was introduced

16、as a complete grapgh design and coding as detail is added to the design. This provides a common language throughout each stage in development. O-O is best applied with specifically designed O-O development tools, but it

17、is important to remember that as a methodology is it not specific to any programming language. Many different programming languages can be used to implement 0-0 technology and design methodologies.Instead of procedur

18、es and functions passing data back and forth, in object oriented design, the system is viewed as a collection of objects with messages passed from object to object. Each object has its own set of

19、associated operations. Object-oriented design is based on the idea of information hiding and modularization of both data and processing. It is best used when neither data structure nor processing operations

20、 are well defined ahead of time. This is quite useful in today's business environment where requirements are always changing and not very well defined. Thus, it has become quite popular! The concept of objects perfor