ISBN : 978-81-963532-2-3 (E-Book) A structure chart represents the software architecture, i.e. the various modules making up thesystem, the dependency (which module calls which other modules), and the parameters that arepassed among the different modules. Hence, the structure chart representation can be easilyimplemented using someprogramming language.Since the mainfocusina structure chartrepresentation is on the module structure of the software and the interactions among differentmodules,theproceduralaspects(e.g.howaparticularfunctionalityisachieved)arenotreprese nted. Thebasic buildingblocks which areusedto design structurecharts arethefollowing: Rectangularboxes:Representsamodule. Moduleinvocationarrows:Controlispassedfromononemoduletoanothermodulein thedirection ofthe connectingarrow. Dataflowarrows:Arrowsareannotatedwithdataname;nameddatapassesfromone module to another module in thedirection ofthe arrow. Librarymodules:Representedbyarectangle withdoubleedges. Selection:Representedbyadiamondsymbol. Repetition:Represented byalooparoundthecontrol flowarrow. StructureChartvs. FlowChart We are all familiar with the flow chart representation of a program. Flow chart is a convenienttechnique to represent the flow of control in a program. A structurechart differs from a flowchartin threeprincipal ways: • It is usually difficult to identify the different modules of the software from its flow chartrepresentation. • Datainterchange amongdifferent modulesisnotrepresentedinaflowchart. • Sequentialorderingoftasksinherentinaflowchartissuppressedinastructurechart. TransformAnalysis Transform analysis identifies the primary functional components (modules) and the high levelinputs and outputs for these components. The first step in transform analysis is to divide the DFDinto3 types of parts: • Input • Logicalprocessing • Output 49 Software Engineering Keerthana P, Manasa KN, Ganga D Bengal
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