开发信息系统外文翻译.docx

1、开发信息系统外文翻译毕业论文（设计）外文翻译Developing Information SystemsIn this and the following chapters, we will discuss different approaches concerning how an organization can obtain its information systems once the decision in favor of a system has been made.While chapter 7 will deal with buying and introducing so

2、ftware that was developed by others, in particular standard software, the focus in this chapter is on how to build completely new information systems or new modules that extend existing information systems within an organization. By new modules we mean that significant development effort is required

3、 in order for the project to pass all stages of the software development process.In contrast to this, limited extensions of a running information system are considered part of the maintenance and support stages. Adding functionality to a new standard software system will be discussed in chapter 7, a

4、s part of the customizing process.The perspective taken in this chapter is that the starting point for the development effort is an approved project proposal (cf. section 2.2.1);i.e., a managerial level decision to launch a project for building a system inhouse has been made. If no restrictions exis

5、ted, we could say that the project starts from scratch. In the real world, however, such restrictions often limit the degrees of freedom substantially.4.1 Starting with a Problem SpecificationConstraints that a new information system development effort may need to observe include the following: The

6、existing information systems landscape has to be considered. Most likely the new system will need to be interfaced with the companys ERP system and other information systems. The platform on which the new system will run is probably outside the scope of the project. If the companys existing systems

7、are all based on IBM Web Sphere, for example, then it is unlikely that a different platform will be chosen for a new system which needs to be integrated. Depending on how closely the system is to be connected with existing systems, its architecture may already be predetermined, i.e., it may have to

8、match the architecture of the other systems. Many projects have to run under a tight budget and meager staffing, limiting the possibilities of what can be done.Despite these constraints, the development of new information systems offers a wide array of options and fewer limitations than customizatio

9、n projects.Any development project needs a specification of the problems to be tackled. The project proposal contains a problem description, but this description is usually just a written text for the approval process, too coarse and not operational enough to identify relevant development tasks. For

10、 this purpose, a more formalized high-level specification of the future system is required.Several approaches to define such high-level specifications have emerged in the past. With business processes nowadays being the dominating paradigm for running organizations, this high-level description of th

11、e IS needs is usually a description of a business process or a sub-process.The process specification could simply be a textual description of the major process steps and the resources involved. Since semi-formal specifications have advantages over text, various graphical notations to specify a busin

12、ess process on a high level have come into existence over the years, including the following: Context diagrams in SA (structured analysis) Yourdon 1989, p. 339 Activity and use-case diagrams in UML (unified modeling language) Event-driven process chains in ARIS (architecture of integrated informatio

13、n systems) Scheer 2005 Business process diagram in BPMN (business process management notation)Figure 4-1 shows just one possible way of visualizing a business process. As many notations for business-process modeling exist, the graphical constructs vary. Besides high-level diagrams, all approaches co

14、mprise a suite of graphical symbols with appropriate semantics as well as methods and tools for different aspects of modeling and construction. As a process is increasingly refined, more symbols and more meanings are added to the high-level representation. Since methods andtools will be discussed in

15、 the following chapter, we do not introduce more notations at this point.4.2 Process Models and ISD ParadigmsAssuming that an operational problem specification has been created, development of the information system can start. There are many ways to conduct the development effort. Templates arrangin

16、g development activities into a specified order are called software process models. (Note that the term process refers here to software development activities and not to business processes as above.) This term can be defined as follows:A software process model is an ordered set of activities with associated results that are conducted in the production and evolution of software. It is an abstract representation of a type