自动售货机 需求报告

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1、VendingMachine1-ObjectivesTheobjectivesofthisexerciseareto:·BasedonTOODdesignapproach,propose2solutionsforthedesignarchitectureoftheVendingMachinepresentedinspecificationmodule:·Firstsolution:sequential-withoutprocess.Usingasequentialsolution,itisinterestingtoshowthanonem

2、odeoftheStateTransitionDiagram(STD)cannotbereached:“DispensingProduct”.·Secondsolution:concurrent-withprocess(es).Hypothesismustbemadeonthehardware.2-ProblemOverviewThisexampleisanextensionoftheproblempresentedattheForum”StructuredDevelopment”inSanFrancisco,inFebruary1986

3、.Theproblemstatementandtheresultingmodelswereinteractivelydevelopedanddescribedasadialoguebetweenthecustomerandtheanalyst.Thecustomerstartedbyoutliningtotheanalystthatheisfacedwithcrooksascustomerswhotryputtingjunkintothecoinslotsofhisvendingmachineshopingtogetsomethingfo

4、rnothing.Someeventrytoentercoin-likeslugstofoolthemachines.Theyalsotrytovandalizetheselectionregistertogetproductsfree.Thesearemajorproblemsforthevendingmachineoperatorsbecausetheydobusinessonanarrowmargin,whichdisappearsveryquickly.Themachineistodothefollowing:-Acceptobj

5、ectsfromthecustomerinpaymentforhis/herpurchase.-Checkeachobjecttomakesurethatitisnotaslug.Thisistobedonebyvalidatingthesize,weightandthickness.-Acceptnickels,dimesandquarters.Anyothercoinsaretobetreatedasslugsandreturnedtothecustomer.-Onlyinitiatepaymentcomputationorprodu

6、ctselectionprocessafteravalidatedcoinisdetected.-Acceptproductselectionfromthecustomer.-Checktoseewhethertheselectedproductisavailable,ifnotavailable,returncoinsautomaticallyandnotifycustomer.-Acceptavarietyofproducts,whichwillchangefromtimetotime.Hence,theproductpricessh

7、ouldbechangeable.-Returnthecustomer’spaymentonrequestifheorshedecidesnottomakeaselection.-Dispensetheproducttothecustomerifitisavailableandtheamountissufficient.-Returnthecorrectchangetothecustomeriftheamountdepositisgreaterthantheproductprice(initialconditions?).-Disable

8、theproductselectionaftertheproductisdispensedanduntilthenextvalidatedcoinisreceived.Severalextra