《軟件工程》期中試題解答

1、軟件工程期中試題一、選擇題：1. The waterfall model of software development is also known as the ( ) A A. Classical life cycle model B. Fountain model C. Spiral model D. Chaos model2. The incremental model of software development is ( ) B A. A reasonable approach when requirements are well defined. B. A good appro

2、ach when a working core product is required quickly. C. The best approach to use for projects with large development teams. D. A revolutionary model that is not used for commercial products.3. COCOMO II is an example of a suite of modern empirical estimation models that require sizing information ex

3、pressed as ( ) DA. function points B. lines of code C. application points D. any of the above4. An effective risk management plan will need to address which of the following issues? ( ) DA. risk avoidance B. risk monitoring C. contingency planning D. all of the above5. The relationships shown in a d

4、ata model must be classified to show their ( ) C A. Width and depth B. Directionality and reliability C. cardinality and modality D. probability and risk6. The data dictionary contains descriptions of each software ( ) BA. configuration item B. data object C. diagram D. notation7. The state transiti

5、on diagram ( ) A A. indicates system reactions to external events B. depicts relationships between data objects C. depicts functions that transform the data flow D. indicates how data are transformed by the system 8. Which of the following is not an area of concern in the design model? ( ) DA. archi

6、tecture B. data C. interfaces D. project scope9. A program design language (PDL) is often a ( ) A A. combination of programming constructs and narrative text B. legitimate programming language in its own right C. machine readable software development language D. useful way to represent software arch

7、itecture10. What types of errors are missed by black-box testing and can be uncovered by white-box testing? ( ) BA. behavioral errors B. subtle logic errors C. performance errors D. input error11. To achieve high modularity of software components you need C A. high coupling and high cohesion B. high

8、 coupling and low cohesion C. low coupling and high cohesion D. low coupling and low cohesion12. Which of the following is not an objective for building an analysis model? C A. define set of software requirements B. describe customer requirements C. develop an abbreviated solution for the problem D.

9、 establish basis for software design13下圖所示的軟件模塊結構圖，該軟件的寬度為（ ）。 DA1 B3 C5 D6 14面向對象的軟件工程中，識別主類主要靠（ ）。 AA經(jīng)驗 B技巧 C啟發(fā)式規(guī)則 D面向對象分析理論15用例圖是（ ）。 DA系統(tǒng)特定行為的描述B系統(tǒng)行為之間交互的描述C系統(tǒng)和外部實體交互的描述D系統(tǒng)特定行為和外部實體以及和其他行為交互的描述二、簡答題：1What are the differences between generic software product development and custom software develo

10、pment? 1.2A：The essential difference is that in generic software product development, the specification is owned by the product developer. For custom product development, the specification is owned by the customer. Of course, there may be differences in development processes but this is not necessar

11、ily the case.2What are the four important attributes which all software products should have? 1.3A：For important attributes are maintainability, dependability, efficiency and usability.3A software architecture describes a high-level design view of a software system. What are the advantages of explic

12、itly describing the architecture independently from the implementation?參考答案（不夠準確）：The architecture may have to be designed before specifications are written to provide a means of structuring the specification and developing different sub-system specifications concurrently, to allow manufacture of ha

13、rdware by sub-contractors and to provide a model for system costing.4Explain why it is important to produce an overall description of a system architecture at an early stage in the system specification process. 2.4A：An overall architectural description should be produced to identify sub-systems maki

14、ng up the system. Once these have been identified, they may be specified in parallel with other systems and the interfaces between sub-systems defined.5Requirements should state what a system should do, without stating how it should do it. Why is this distinction useful?6Define black box and white b

15、ox testing. What are the advantages of each approach ? Why are both necessary?7Full path coverage testing requires that every possible path through the code be tested at least once. Why is full path coverage testing desirable? For the code fragment above, how many test cases would be needed for full

16、 path coverage? Why might full path coverage be impossible to achieve for some programs?8Why is software maintenance difficult? Why is it necessary?9If you want develop an interactive system that allows railway passengers to find train times from terminals installed in stations, which generic softwa

17、re process model that more suitable to management the development process? And why? A：Interactive timetable System with a complex user interface but which must be stable and reliable. Should be based on throw-away prototyping to find requirements then either incremental development or waterfall mode

18、l.10Describe four types of non-functional requirements that may be placed on a system. Give examples of each of these types of requirement.A：There are many possibilities here. Some suggestions are shown in Figure 6.4.Figure 6.4 Non-functional requirementsNon-functionalrequirementDescriptionDescripti

19、onPerformancePerformance requirements setout limits to the performanceexpected of the system. Thesemay be expressed in differentways depending on the type ofsystem e.g. number oftransactions processed persecond, response time to userrequests, etc.The system must process at least 150transactions per

20、second.The maximum response time for any userrequest should be 2 seconds.ImplementationDefines specific standards ormethods which must be used inthe development process for thesystemThe system design must be developed usingan object-oriented approach based on theUML process.The system must be implem

21、ented in C+,Version 3.0.UsabilityDefines requirements whichrelate to the usability of thesystem by end-users.All operations which are potentiallydestructive must include an undo facilitywhich allows users to reverse their action.(This is an example of a functionalrequirement which is associated with

22、 a nonfunctionalrequirement)All operations which are potentiallydestructive must be highlighted in red in thesystem user interface.SafetySafety requirements areconcerned with the overall safeoperation of the systemThe system must be certified according toHealth and Safety Regulations XYZ 123.三、綜合題1T

23、he following table shows the estimated activity durations and pre-requisites for a project development. Activity Description Duration(weeks) Task Pre-requisites T1 Requirements Elicitation 4T2 Analysis & Design 3 1 T3 Install hardware 2 1 T4 Design Review 1 2 T5 Code & Unit Test 4 1,2,3,4 T6 Integra

24、tion Test 2 5 T7 Porting Software 1 4,6 T8 Documentation 2 6,7 T9 Acceptance Test 3 5,6,7 T10 Install & Train 2 9 Draw a activity chart to determine the earliest week of completion, the activities which have some float or slack, and the activities on the critical path. Draw a bar chart showing the p

25、roject schedule.2繪制打電話的狀態(tài)轉換圖3某校教務系統(tǒng)具備以下功能，輸入用戶ID號及口令后，經(jīng)驗證進入教務管理系統(tǒng)，可進行如下功能的處理：查詢成績：查詢成績以及從名次表中得到名次信息。學籍管理：根據(jù)學生總成績排出名次信息。成績處理：處理單科成績并輸入成績表中。就以上系統(tǒng)功能畫出0層，1層的DFD圖。 教務系統(tǒng)0層DFD 圖 教務系統(tǒng)1層DFD 圖（身份驗證處理框對應有一個用戶信息的存儲，名次表和學生成績表應用存儲的表示法）4一個自動化圖書館目錄的軟件系統(tǒng)要被開發(fā)。這個系統(tǒng)將要包含圖書館中所有圖書的信息，要求該系統(tǒng)對圖書管理員、借閱者和讀者都可用。該系統(tǒng)應該支持目錄瀏覽、查詢，允

26、許用戶發(fā)送消息給圖書管理員預訂一本在借圖書。識別出系統(tǒng)描述中應考慮的基本視點，并用視點繼承圖（層次圖）來描述它們之間的關系。 6版6.2題A：The viewpoints are shown in Figure 6.1. Note that system management (i.e. thoseresponsible for installing and maintaining the computer system are a viewpoint aswell as library staff and library users. Library users have been sepa

27、rately identified asbrowsers and searchers as these operations typically require different types of services.Figure 6.1 Viewpoint hierarchy diagram5Develop an object model, including a class hierarchy diagram and an aggregation diagram showing the principal components of a personal computer system a

28、nd its system software. 8.8A：There are many possible organizations for the class hierarchy. I show a simple one in Figure 8.4 with only two levels. A three-level hierarchy would also be OK but more than that would be too much. The aggregation diagram shows the part-of relationships between objects.

29、This is shown in Figure 8.5. Obviously, further decomposition of the lowest level is possible.Figure 8.4 Class hierarchy for a PCFig 8.5 Aggregation diagram for a PC6Develop a sequence diagram showing the interactions involved when a student registers for a course in a university. Course may have limited enrolment, so the registration process must include checks that places are available. Assume that the student accesses an electronic course catalogue to find out about available courses. 8.9 A：See Fig