专业英语翻译unit 4.ppt

The major objective of structured system analysis and design is to determine the exact system requirements so that the “right” system is designed. The structured approach employs a series of graphic tools and techniques that the user can fully understand. This method enables analysts to catch errors in analysis before they become inputs into the design and subsequent phases of the systems development process. If an error is caught during the analysis phase of a project, the cost of correcting it is many times lower than the cost of correcting the same error once the system has been designed and is in operation. For example, if a necessary data element is not identified during the analysis phase, it may be left out of system files during the design phase. Once the system is in operation, a user may notice that certain information is missing from a report. The designer may look into the situation and find out that a data element is missing from a master file. Redesigning the file and the report would take much more time than adding the data element to a data dictionary the analysis phase of the project. The process of structured systems analysis helps analysts catch errors early. Instead of giving users pages of system specifications that they cannot understand, the structured systems analysis process uses tools that depict a logical model of the current system and of the proposed system that the user can clearly understand. The structured approach to systems development is compared to the traditional approach in table 4.1. The traditional approach calls for studying the current system, including its data files, reports, procedures, and decisions, and developing an automated version of the system. Although this approach is efficient, there is a tendency to automate the inefficiencies of the current system. Reports could be produced for no reason in the current situation. Information about applicants could be incomplete, out of date, or