《系统工程》课程教学资源（英文文献）Enhancing simulation software for use in manufacturing.pdf_大学文库

IntroductionEnhancing simulationDesigning manufacturing systems beforesoftware for use inimplementing them in practice is a task thatmanufacturingsimulation modelling is ideally suited to,given the complexity and dynamic andstochastic behaviour of such systems. One ofL.P. Baldwinthe advantages of using simulation is that itT. Eldabican be used to provide a high level ofV. Hlupic andutilisation of manufacturing facilities in bothSMEs and larger organisations by ensuringZ. Iranithat any bottlenecks or problems which mightprevent a smooth and uninterrupted flow ofThe authorswork are reduced or eliminated. Anotherbenefit is that simulation provides a betterL.P. Baldwin and T. Eldabi are Lecturers, and V. Hlupicunderstanding of the behaviour of theand z. Irani are Senior Lecturers, all in the Department ofcompletemanufacturing system within anInformation Systems and Computing at Brunel University,SME (or larger organisation), or particularUxbridge, UK.parts of it. As many problems relating to thedesign and operation of manufacturingKeywordssystems are usually too complex to allowManufacturing systems, Computer simulation,rigorous mathematical treatment, it is notSoftware development, Europe, Logisticspossible to represent such problems bymathematical relationships without having toAbstractmake a very large number of assumptions.The mathematical relationships can thereforeThe design of manufacturing systems is a complex andno longer represent, in a realistic manner, theexpensive task for both SMEs and large organisationsproblem being investigated.Such problemsalike. Many problems relating to the design and operationcan, however, be investigated byof manufacturing systems are too complex to allow forexperimentation, although in the workplace itmathematical treatment,andasaresultthereisis very difficult, or often impossible, to carryincreasing recognition of the applicability of simulation inoutexperiments on theactual manufacturingthe manufacturing environment. This has in turn resultedsystems themselves. Simulation can usefullyin a growth in simulation software products available inbe employed to carry out such experimentsthe marketplace, and manufacturers of such products are(Kochhar, 1989).Pegden et al. (1990)naturallykeentoextol thevirtues of whattheysell.Inahighlight a further benefit of using simulationrapidlychangingworkplace,thereissomesuggestionthatmodelling techniques, namely that they cansimulation tools may not have developed to deal with thebeused to predict the behaviour of complexnew demands, and so it is timely to review what is onsystems by calculating the movement andoffer. This paper presents the results of a survey ofinteractionofsvstemcomponents.PegdenetEuropean simulation specialists, both working in industryal.(1990)go onto saythat simulationallowsand in an academic environment, on the use of simulationfordetailed analysisandevaluationofnotsoftware. The main purpose of this survey was toonly physical layouts but also equipmentdetermine how satisfied users are with simulationselections and operating procedures as well.software and to highlight the most positive and negativeEvaluation of the movement of parts throughfeatures. The findings offer an insight into currentthe machines and workstations, together withsoftware, and how this can be further enhanced.examination of the conflicting demands oflimited resources, at thedesign stage, haveElectronic accessclear benefits in terms of increased efficiencyThe current issue and full text archive of this journal isand lower costs.It is true to say that computeravailable atsimulation has now become one of the mosthttp://www.emerald-library.comwidely used techniques in manufacturingsystems design, as it enables both decisionmakersandmanufacturing engineers in bothLogistics Information ManagementSMEs and large organisations to study theVolume 13 - Number 5 - 2000 - pp. 263-270MCB University Press -ISSN 0957-6053complexityoftheirsystemsandhowchanges263

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Enhancing simulation software for use in manufacturingLogistics Information ManagementLP. Baldwin, IT.Eldabi, V. Hlupic and Z. IraniVolume 13 - Number 5 - 2000 :263270in system configuration or operating strategylanguage. Although this approach providescan affect overall performance.flexibility,it is time consuming and expensive.Thegrowingpopularity of simulationhasSMEs, as with all organisations, need to makeresulted in a growth in the number ofeffective use of limited time and resources,simulation languages and simulators availableand costs incurred of buying the softwareon the softwaremarket (Hlupic, 1994; Lawneed to be balanced against the assumedandMcComas,1997).Although spacedoesbenefits.A simulatorallows themodelling ofnot permit here to list all of the latest products,the problem with little or no programming,a few ofthem are now described, as these give awhich might significantlyreduce the"flavour"of the literature.With the currentmodellingtime,butonlyifthesystemunderinterest in object oriented design, Healy andconsideration fits the domain of the package.Kilgore(1997)promotethevirtuesofmodelGiven theparticular difficulties of SMEs,itsimplicity and reusability of Silk, a generalmay well be useful for them to further explorepurpose language which has its roots in thelinks with academic institutions, asprogramminglanguage Java.They go on to sayinformation systems orcomputersciencethat Java and other Internet relateddepartments will be able to provide usefultechnologies have the ability to deal with thesupport. It is likely that SMEs do not haveshortcomingsofsimulationtoolsalreadyinsufficient numbers of modellers, orexistence, and that Silk will encourage bettersufficientlywideexperienceofmodelling,sosimulation. Quite how this is achieved is notthey may benefit from closer links withexplained, unfortunately.Pritsker and O'Reillyacademic institutions in that such expertise ismore readily accessible, and available.With(1997) describe AweSim, a new generalpurpose simulation system which has thesuch a wide choice of simulation toolsadvantage of "openness and interconnectivity"available, choosing one is not an easy task,Particularly for an SME with limited(p.545)to standard word processingprograms, spreadsheets and databases.Yetmodelling experience. As the aboveanother new simulation system is described bydemonstrates, the claims that the creators ofEhrlich and Lilegdon (1997,p. 565), who extolsuch tools make are persuasive, with eachthe virtues of FACTOR/AIM, a simulationpromising efficiency and effectiveness and allsystem specifically designed to be used in thefor less time and money.decision support of manufacturing. ThisThis paper reports not on the claims of thedesigners of these new, or not so new,system, say the authors,makes modelling easierand faster and allows decision makers moresystems, but on those who use them. It will betime to think about their decisions, and thusinteresting to see whether the claims made forcome up with better decisions that can onlythe softwaremeet the expectations of thoseserve to enhance the manufacturing processes.who buy them. Given the high cost of many ofSLX is, according to its designers, “a well-these, choosing the appropriate tool for thetask is important for both SMEs and largeconceived, layered simulation system"whichhas all the convenience of a high-level packageorganisations alike, not only in terms of(Ehrlieh and Lilegdon, 1997, p.565). Incapital outlay but in time and effort as well.contrast to the novelty of Silk, FACTOR/AIMThis paper presents and discusses the resultsand SLX, Crain (1997)iskeen to point out theof a survey on the use of simulation software.superior qualities of GPSS/H which, althoughA survey of a number of European simulationnot new, is"one of the most general, flexiblespecialists, both in the industrial andacademic environments, was carried out toand powerful" simulation tools on themarketplace today, and is used in a wide varietydiscover whether users are satisfied with theof working environments (p.567).Particularlysimulation software they use, and how thisuseful for manufacturing is SiMPLE++, say itssoftwarecan befurther improved.Despitethecreators,Kalasky and Levasseur (1997),whoupbeat tone of the creators of the toolsclaim that it is “a highly efficient, highly flexibledescribed earlier in this section,tool" which has been used successfully in manyimprovements are clearly needed as,organisations throughout the world.according to Pratt andBeasley (1997),Whether using this language or any other,although the needs of the workplace havewhen a model is developed using a simulationchanged, simulation tools have not altered atlanguage, the simulation analyst has to writeathe same pace, and more efficient andprogram usingthemodelling constructs oftheeffective ones are required, both in SMEs and264

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Enhancing simulation software for use in manufacturingLogistics Information ManagementVolume 13 - Number 5 - 2000 : 263270LP. Baldwin, T. Eldabi, V. Hlupic and Z. Iranilarger organisations.Kreutzer et al. (1997,sample of simulation packages according tovarious criteria. On the basis of the responses,p.483)concur, saying that commercialsimulation tools have not developed alongsidethey classified the software evaluated intothe rapid pace of technological change andclusters according to the main softwarefeatures.Kirkpatrick and Bell (1989)used athat, as a result, many popular simulationtools today “are riddled with non-intuitivesurvey approach to investigate the issuesinterfaces and inconsistent and unnecessaryrelatedto visual interactivesimulation inrestrictions". In their view, it is not possible toindustry, reporting that these issues includeanticipate everything that any given user willthe types of problems being addressed,need, and that good tools must allow for safereasons for using visual interactive modelling,and convenient extensions, refinements andand the ways in which this type of modellingadditional layers.Following a brief review ofaffectsproblemsolving.Theresultsrevealedsimulation research in the area of simulationthat although some of the participants weresoftware analysis using the survey method, aaware of the significant set-up costs and thedescription of the actual survey is presented,demands associated with learning newand the results obtained are examined andsoftware and a new methodology, mostdiscussed. The conclusions outline the mainparticipants agreed that visual interactivemodelling provides enhanced interaction withfindings of this research.decision makers, more useful and easier-to-understand models, and better decisions.The main findings to be drawn from theSurveys of users in the simulationanalysis of simulation research studies dealingliteraturewith users' surveys reveal that although themajority of the survey studies investigateBefore the questionnaires for the survey usedissues related to simulation software, none ofin this research were designed, a literaturethem have examined the opinions oftheusersreview was undertaken in order to findthemselves about possibleways in which theexamples of any similar previous studies.Thissoftware could be improved.review found several examples of userssurveys in the simulation literature, althoughmany were, like the survey carried out byKleine (1970, 1971), somewhat dated.A survey of simulation software forKleine's research examined users'views of 11manufacturingdiscrete simulation languages. The results ofThe main purpose of the survey was tothis survey showed that it was difficult tointerpret the results, and that this was mainlyinvestigatetherequirementsofEuropeandue to the fact that there was a limitedusers of simulation software, and especially ofnumberofrespondents whowereproficient insoftwareused for manufacturing simulation,with a view to soliciting their opinions aboutmore than one language.In addition, theexpertise of some respondents was difficult towaysof improvingcurrentsimulationsoftware tools to better satisfy their needs.specify.Christy and Watson (1983)used asurvey of non-academic users to exploreThe questionnaire distributed to theissues such as thefunctional areas that useparticipantsinthesurveyconsistsof ninequestions dealing with the type of simulationsimulation, the method of selectingsoftwareused (Figure 1),the specification ofsimulation software, the popularity of variousparticular packages used (WITNESS,softwaretools for simulation applications andSIMFACTORY II.5, SIMAN/CINEMA,other suchfactors.TheiranalysisrevealedProModelPC,XCELL+,INSTRATA orthat ofthetotal applications of simulation,59 per cent were in the area ofmanufacturingFigure 1 Type of software usedsystems.For simulation software, the resultsshowed that there is a widespread reluctanceto implement and learn new programming38%DSIMULATCRlanguages for simulation applications. VanBSIM&LANGLAGEBreedam (1990)conducted a survey in order57%DLANGUAGESto evaluate several simulation software tools.Experienced users of simulation were given a5%questionnaire to complete in order to rate a265

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Enhancing simulation software for use in manufacturingLogistics Information ManagementLP. Baldwin, T. Eldabi, V. Hlupic and Z. IraniVolume 13 - Number 5 -2000 :263270other) (Figure 2),the purpose of usingFigure5Asummaryofusersopinionsaboutthemainlimitationsofthesimulation (Figure 3),general opinions aboutsoftware usedeach software item used (Figure 4) and the36%types of systems being modelled (Figure 5)30%Otherquestionsincludeanestimationofhow25%successful the simulation studies carried out20%were from the point of view of the software15%used (Figure 6). In particular, users had to10%appraise whether substantial approximations5%0%hadto be made due to limitations of theQ1Q2Q304Q5software, or whether all desirable features ofQ607the systems under consideration could beQuestions askedmodelled.The participants were also asked toQI:Restricled BexibilityQ2:SlolistthemainweaknessesandlimitationsoftheQ3:Validaticn difficultiessoftware used (Figure 7), as well as the mostO4:Lack of facilityfoeouputarahysisQS:DiffictittouseDifficult o lenFigure 2 Number of packages usedLack of facility foeouput analysisPoce statistics3%5%Mamufacturing hias and tenminclogy pnoblemQ6:Lackofdataluse linkages13%LimitstosizeofmodelsD1PACKAGEEspensive2PACKAGEQ7:Inodequate graptics5%D3PACKAGELack ofgood suppont foe fluid procesingD4PACKAGELack of good suppont fieobjacl oricmed conceptsBig models are mol understandahle10%SPACKAGE64%D6PACKAGEFigure 6 A summary of users' opinions about the most important positivefeatures of the software usedFigure 3 Purpose of simulation40%8%CMOD.REAL30%39%SYSTEMS25%BEDUCATION% ef U6ers 20%53%15%DMOD.REALSYS10%&EDU%J08%0%Q10293040506CuostionshsdFigure 4 A summary of users' general opinions about the softwareQFGraphics (animgtion)O2Fane ofurseQ:Ease oflearing40%Automatic repont. generationQ4:Imeractivity30%Ulser suppertUser inierface20%Sped ofmodillingQ5:FirsibilityDocuntentation10%Good statisaical analysis6:Imerfiace with other sodtwere0%Sappont foe UNIX plalformsQ1Q2Q3Q4Incorpcealed cod amailysisQ5QBQ7Q8Eaay chst ofwhai-ifquestionCheapQL:Too linited for complexproHemBeing mxnu drivenQ2:Good graphics03:SowQ4:Easy totseimportant positive softwarefeatures (Figure8).Generally very good interactiveQ5:Easy to leamFinally,they were asked to specify the mostBiuscdwosimulationproemQ5:Pocr statistical supportimportantfeaturesthatshouldbeincludedinUar friendlyQ7:Dificuit to validateexisting simulation packages, and that are toInsdeqaate esperimentation facilitiesthebestoftheirknowledgenotyetprovidedDificuk touse Sornon standard problemsQ8:Quick(Figure 9). The majority of the questionsLack of good support for fluid processingregarding opinions about the software, and266

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Enhancing simulation software for use in manufacturingLogistics Information ManagementLP. Baldwin, T. Eldabi, V. Hlupic and Z. IraniVolume 13 -Number 5 -2000 .263270The sample frame and response rates ofFigure 7 Type of systems simulatedthe survey23%The survey sample includes a number ofSONGMAN.SYSregular simulation users both in educationalinstitutions and in industrial companiesBMANUFACT&OTHERSaround Europe.The survey sample was notOOTHERselected by any formal statistical method, and41%the participants, known or believed to beregular users of simulation, were selecteddeliberately.It was intended to obtain aFigure 8 The modelling success from simulationssample of users experienced mainly in usingsimulators (referred as simulation packages in31%31the questionnaire) rather than languages.DALLFEATUREMOOELResponse was moderate, with 30 per cent ofMOSTFEATURESMOCELDMJORPROBLEMSthe 120 distributed questionnaires beingreturned. It should be noted that the ratio ofresponses from universities (70 per cent) and38%responsesfromindustry(30per cent)did notmatch the distribution of questionnaires,Figure 9 A summary of users' opinions about the features that should bewhere an equal number of questionnaires wasincluded in simulation softwaredistributed to each group of users. It is18%interestingtonotethatnot onlywasthe16%numberofresponsessignificantlyhigherfrom14%users from universities, but that on average12%each response from a university provided%orUsens 10%more information than the response from8%users in industry.Further research might6%usefully reveal why this was the case. These4%figures raise the question of the statistical26significance of the results obtained. Although0%Q1Q2Q3O4C56Q7there are as yet unanswered questions as to0809Q10Q11Quesiors Asksdthe response rates, the authors neverthelessclaim that the selecting of participantsQ1:Better sodtware compatibility8Link to datatoseexperienced in simulation serves to justifytheLink to spreadshieets04:Lisk to CAD sofisareimportance of the results, as such users areQ5:Link to statistical packagevery much representative of those who useOLinktoMRPsthedalingQ7:Facilityforoatput analysissimulation tools.QS:More flexibilityHep inesperimemal designQ9:Betcrandmoreiteligoton-linehcipResults of the surveyBetcrExperimenttionfaciliticwFigure 1 shows the results obtained regardingSuppoet standard progranming oonceptQt0:Eliminaticnfmemocylinitstionsthe type of software used. A majority of theBetter docunertationEasy model editingusers use only simulators (56.5 per cent), 38.4Dedicated systemsfoespeeifieapplieationsper cent use both simulators and languages,Highcr esecuion spend01lAhility to cresde run-ine seplicitionand 5.1per cent use only simulationlanguages.AuiomotivesaxeAn analysis of the number of simulationMoreprompttosaseHierarchikcal modelbuildingsoftware tools used reveals that a majority (64.1LoweostsoftuareEany cost ofcn-linereportsper cent) of the users use only one softwareAvailahility on slundrd hedwire ind sotlwire systermstool, but the other 35.9 per cent of users usemore than one software, up to six differentpossibleways of improving it (questions 4,6,software packages as shown in Figure 2.7,8 and 9), were open-ended.Open-endedRegarding thepurpose of simulation,38.5perquestions are, in the view of the authors,centofparticipantsusesimulationonlyforpreferable as they are more likely to generatemodelling real systems, 7.7 per cent useless biased responses than can be said to besimulation only for education, whilst thethe case with closed questions.majority of 53.8per cent use simulation both267

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Enhancing simulation software for use in manufacturingLogistics Information ManagementVolume 13 - Number 5 - 2000 : 263270LP. Baldwin, T. Eldabi, V. Hlupic and Z. Iranifor modelling real systems and education asthat a larger proportion of completedillustrated inFigure3.Common elementsfromquestionnaires were received from academicthe responses regarding general opinion aboutusers as opposed to users in industry. It alsothesoftwareusedaresummarisedinFigure4,indicatesthatmanyacademicparticipantsintogether with the percentage of users that havethe survey, often criticised for dealing withspecified a certain software feature.more theoretical rather than practicalmatters,Figure 5 summarises the responsesare, in fact, involved in research and workingregarding the main limitations andon real, practical, projects.The percentage ofweaknesses of the software used including theparticipants that were involved only inpercentages of the certain responses, whilsteducation (at least concerning simulation)isFigure 6 summarises the responses regardingrelatively low (7.7 per cent), which supportsthe most important positive features of thethe observation concerning the diversity ofsoftware used.activitiesperformedinanacademicWith regard to the types of systems beingenvironment.modelled, 35.9 per cent of users model onlyThe general opinion voiced about themanufacturing systems, 41 per cent aresoftware used was that it was too limited forinvolved in modelling both manufacturingcomplex and non-standard problems.and other types of system, whilst 23.1 perHowever, the majority of users generally hadcent model only other types of systems aspositive opinions about the software theyshown in Figure 7.When being asked aboutused, favouring the interactivity and graphicalthe success of modelling, 30.8 per cent offeatures of simulation software, and ease ofparticipants declared that they have been ableuse and learning.They were not, however,to model desirable features of the systemssatisfied with the running speed, statisticalbeing modelled, 38.4 per cent have managedsupport, experimentation facilities and biasto model most of the features, whilst 30.8 pertowards manufacturing problems.Analysis ofcent had problems. These results arethemainweaknesseslisted showsthattheillustrated in Figure 8.Finally, a summary ofmain limitation in the eyes of the users wasthe features that users would like to havethe limited flexibility of the software beingincorporated in the simulation software thatused. Further problems in this area includedcould improve the software theyuse isinadequate speed of running,validationpresented in Figure9.difficulties, a lack of facilities for outputanalysis and experimental design, poorstatistics, difficulties in learning and use, andsoftware speed.Only a small percentage ofFindings from the surveyusers considered simulation software to beAn analysis of the above survey results raisesexpensive,to have inadequate graphics, toseveral importantpoints.Concerning thetypelack support forobject oriented concepts orof software being used, users who use onlysupport for fluid processing.With regard to the most important positivesimulation languages were in a minority. It isfeatures of the software being used, it isevident that survey participants preferredusing simulators instead of doing bespokenotable that a majority of participantsprogramming.With regard to thenumber ofspecified graphics as the most beneficialsoftware packages used, a majority of userssoftware feature.The second best feature wasused only one simulation software tool (64.1ease of use. Other features included ease ofper cent),whichwasprobablybecause of highlearning,automatic report generation,software prices and the lack of expertise ininteractivity, modelling speed and goodusing a variety of software tools.The majorityinterfaces.On the minus side, not many usersof users who used more than one packageconsidered flexibility,statistical facilities,were working in academic institutions, wheredocumentation, incorporated cost analysis ormore packages are available due to thesoftware compatibility to be either of goodquality or distinctive advantages of theeducational discounts given by softwaresoftware they used.suppliers. Regarding the purpose ofFinally, examination of thefeatures thatsimulation,itis interestingthatthemajorityof users (53.8 per cent) used simulation bothusers would like to be incorporated infor education and modelling real systems,simulation software shows that betteralthough an explanation for this may well besoftwarecompatibilityisofparamount268

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Enhancing simulation software for use in manufacturingLogistics Information ManagementLP. Baldwin, IT. Eldabi, V. Hlupic and Z. IraniVolume 13 - Number 5 -2000 :263270importance. In order of importance withindata driven simulators instead of doingthis, links to databases are most called for,bespokeprogramming.followed by links to spreadsheet software andIt appears that the majority of users wouldthen to other types of software. Furtherlike these packages to be more flexible, and toimportant features specified included a facilitysee additional features that would makefor output analysis, more flexibility and helpmodelling easier and faster. The creators ofin experimental design. Some users alsoSilk, AweSim, SLX and others claim, as canrequested features such as an improvement inbeseeninan earlier sectionofthispaper,thatdocumentation, better and more intelligenttheir simulation tools or languages do indeedon-line help, easier model editing, and higheraid faster and easiermodelling, but it isexecution help. A very small numberdifficult to see how this promise can be bornedemanded featuressuchastheabilitytoout without amore systematic analysis ofthecreate run-time applications, automatic save,complexrelationshipbetween taskdifficultyhierarchical model building, easy design ofor size, simulation tool and user, and size ofon-line reports or cheaper software.organisation. Given the lack of research onsimulation modelling tools as seenfrom theperspective of the user, the findings of thisConcluding commentspaperrepresenta welcomefirst steptowardsabetterunderstanding of how users themselvesThe main purpose of the survey carried out asdefine"easier"or“faster"”and how theypart of this research was to determine howmight best be supported in their tasks.satisfied European simulation specialists, asusers,arewith simulation software.Analysisof their views can thus offer insights into howReferencessuch software can be further improved tomeet users'requirements. Overall, resultsChristy, D.P. and Watson, H.J. (1983), "The application ofsimulation: a survey of industry practice",obtained show that the simulation softwareInterfaces, Vol. 13 No. 15, October, pp. 47-52.currently being used by all participants in thisCrain, R.C. (1997), "Simulation using GPSS/H"survey is well regarded in that it is easy to use,Proceedings of the 1997 Winter Simulationvisual, and interactive. Participants are,Conference, Atlanta, GA, 7-10 December,however, very critical of the software in that itpp.567-73.is too limited for complex and non-standardEhrlich, J.N. and Lilegdon, W.R. (1997), "Making bettermanufacturing decisions with AIM", Proceedings ofproblems, too slow, and that it is biasedthe1997 Winter Simulation Conference,Atlantatowards manufacturing problems.GA, 7-10 December, pp. 552-8.Features that these users are keen to seeHealy, K.J. and Kilgore, R.A. (1997), "Silk: a Java-basedincorporated into simulation software includeprocess simulation language', Proceedings of thebetter softwarecompatibility,moreflexibility,1997 Winter Simulation Conference,Atlanta,GA,and more systems dedicated to specific7-10 December, pp. 475-82.Hlupic, V. (1994),"Manufacturing simulators:anapplications (although this is puzzlinglyevaluation and comparison",International Journalcontradictory),a provision offacilities forof Manufacturing System Design, Vol.1 No.3,output analysis and experimental design, andpp. 177-85.bettermodellingassistance(forexampleKalasky, D.R. and Levasseur, G.A. (1997), "Usingeasier editing and better on-line help).SiMPLE++ for improved modeling efficiencies andAlthough the majority of survey participantsextending model life cycles", Proceedings of the1997 Winter Simulation Conference,Atlanta,GA,were academics, who are often criticised for7-10 December, pp. 611-18.their over-theoretical stance, a very smallKirkpatrick, P. and Bell, P.C. (1989), "Visual interactivepercentage of all users use simulation only formodelling in industry: results from a survey of visualeducational purposes, which indicates that ainteractive model builders", Interfaces, Vol. 19varietyofsimulationstudieshavebeencarriedNo. 5, September-October, pp. 71-9out in real life manufacturing (and other)Kleine, H. (1970), "A survey of users' views of discreteenvironments. Furthermore, a majority ofsimulationlanguages",Simulation,May.pp.225-9Kleine, H. (1971), "A survey of users views of discreteusers use only one simulation softwaretool,simulation languages (the second survey)".apparentlybecause of the high software pricesSimulation, August, pp. 89-94and a lack of experience or expertise in usingKochhar, A.K. (1989),"Computer simulation ofdifferent simulation software tools.Themanufacturingsystems-3decadesofprogress",inMurray-Smith, D., Stephenson, J. and Zobel, R.N.results also indicate that users prefer using269

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Enhancing simulation software for use in manufacturingLogistics Information ManagementLP. Baldwin, T. Eldabi, V. Hlupic and Z. IraniVolume13-Number5-2000-263-270(Eds), Proceedings of the 3rd European SimulationModeling Corporation, NJ and McGraw Hill, Inc.,New York, NY.Congress, Edinburgh, the Society for ComputerSimulation, San Diego, CA, pp. 3-9.Pratt, D.R. and Beasley, D.W. (1997), "lssues in modellingKreutzer, W., Hopkins, J. and van Mierlo, M. (1997)and simulation: policies and technologies","SimJAVA - a framework for modeling queuingProceedings of the 1997 Winter Simulationnetworks in Java", Proceedings of the 1997 WinterConference, Atlanta, GA, 7-10 December,Simulation Conference, Atlanta, GA, 7-10pp.369-72.December, pp. 483-8.Pritsker, A.A.B. and O'Reilly, JJ. (1997),"AweSim: theLaw, A.M. and McComas, M.G. (1997), "Simulation ofintegrated simulation system", Proceedings of themanufacturing systems", Proceedings of the 19971997 Winter Simulation Conference, Atlanta, GA,Winter Simulation Conference, Atlanta, GA,7-10 December, pp. 545-51.7-10 December, pp. 86-9.Van Breedam, A. (1990), "Segmenting the simulationPegden, C.D., Shannon, R.E. and Sadowski, R.P. (1990),software market", OR Insight, Vol. 3 No. 2,Introduction to Simulation Using SIMAN, SystemsApril-June, pp. 9-13.270

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