外文翻譯--軟件工程之需求分析和系統(tǒng)性能評價

1、附 錄附錄 A 英文原文Requirements Analysis And Evaluating a System’sPerformance of Software EngineeringRequirements AnalysisThe first questions a businessperson，such as the manager of a department，should consider are：“What need

2、s to be done better in my business？” and “Will a computer help？” ．Of course，that person might have a difficult time specifying exactly what needs to be done more efficiently in his or her business．And，there are

3、cases where managers introduce computers into their departments without understanding their applications．For example，suppose a small firm does not have a working manual accounting system but contracts the job to an accou

4、nting service because no one in the firm really understands accounting．A computerized accounting system might be difficult to implement or，worse yet，might aggravate the accounting problem．However，thinking about

5、 a new computer system is an ideal opportunity for businesspeople to reexamine their business and the manner in which it is operated．The starting point for the requirements analysis is a review of the potential applica

6、tions．Making a requirements list of your applications can be done in a simple，nontechnical way．First，make a list of potential applications．Then，write a description of each applications and decide whether it can jus

7、tify needing a computer system．Also include in the description how much time will be spent using the application．When people begin to describe their applications，it becomes easier to picture more concrete use

8、s and functions for computer systems．The descriptions will serve as guidelines in later phases of the life cycle．For example，let us examine the case of two secretaries：one is an executive secretary for the president of

9、a firm and the other is a legal secretary for a law firm．The executive secretary is primarily interested in a word processing application to handle business correspondence，which consists of letters，memo

10、s，and brief proposals that flow through the office ．The secretary will use word processing on a daily basis，but only for brief periods during the day．As the secretary begins to describe the appli

11、cations，he finds out that most of the documents are under three pages and that a word processing package that is easy to learn and use ? Will a computer help？ ? What is the system required to do？? What are some prelim

12、inary approaches to the problem？Evaluating a System’s PerformanceOperational software was designed to improve the efficiency of computer systems．DP professionals are constantly looking for signs that their comput

13、er hardware is not performing effectively．Processing delays，slow response times，frequent error states，and longer processing cycles are just a few of the signs of malfunctioning operational software．Examples of these typ

14、es of inefficiencies are readily apparent in online processing systems．File inquiries that normally might take fractions of seconds now require seconds to complete．Processing time for programs in the job increases by 20

15、 to 40 percent for no apparent reason[1]．There are complaints about increased response times in both peak and off-peak periods．These and other operational difficulties may signal that an operating system is under stres

16、s．Though these examples may indicate inefficiencies in the operational software，they are insufficient for the systems programmer monitoring that performance．Programmers need more precise operational data upon which to

17、base their analyses and evaluations．Manufacturers accordingly modified their operational software to provide such statistics．This area of specialization，known as performance management，provides the data needed to

18、 evaluate a system’s level of performance．The performance management software is built into the operating system and can provide statistics relating to：1.The number and type of I / O operations and time required to pe

19、rform them．2.The volume and frequency of access to files in the entire system．3.The average response time needed to handle online inquiries．4.The frequency of access to specific disk drives and the files maintained on t

20、hat device．5.The volume of telecommunication traffic handled by specific channels．6.The usage times associated with all I / O devices．7.The amount of available CPU space during peak periods．8.The average time needed to

21、process a tast in the job queue，broken down into waiting time and actual processing time．9.The frequency of use of the system’sutility software．10.The frequency of execution for all software run with the system．These st