Logic ModelingStructured EnglishStructured English versus PseudocodeSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Logical DFD Activities 3 and 4: Generate orders & pay orderSlide 13Structured English for Process 1.0Structured English for Process 2.0Structured English for Process 3.0Structured English for Process 4.0Logic ModelingRepresents the internal structure and functionality of the processes represented on data flow diagramsStructured EnglishA modified form of the English language used to specify the logic of information systems processesStructured English versus Pseudocode•Structured English resembles spoken English•Structured English uses a subset of the English vocabulary to express information system process procedures•Pseudocode resembles a programming languageStructured English versus Pseudocode•Sequence, Conditional, Repetition•Mimics indentation format utilized in programming languages•Does not include–Variable initialization–Open/close of files–Logic for matching files•Communication Tool for analysts and users•Sequence, Conditional and Repetition•Initializes Variables•Opens/closes files•Requires logic for matching files•Communication tool used for programmers and analystsStructured EnglishPseudocodeStructured English•Three Processes Of Structured Programming–Sequence–Conditional Statements (Decision)•IF•CASE–Repetition•DO UNTIL•DO WHILEStructured EnglishIF StatementBEGIN IFIf Quantity in stock is less than reorder point THEN GENERATE OrderEND IFStructured EnglishCase StatementSELECT CASECase 1 (Grade is A)Multiply credit by 4 to get grade pointsCase 2 (Grade is B)Multiply credit by 3 to get grade pointsCase 3 (Grade is C)Multiply credit by 2 to get grade pointsCase 4 (Grade is D)Assign credit to grade pointsAll other casesgrade points = 0END CASEStructured EnglishDO UNTILDOREAD next Inventory RecordBEGIN IFIf Quantity in stock is less than reorder point THEN GENERATE OrderEND IFUNTIL end of file (Inventory)Structured EnglishDO WHILEREAD first inventory recordWHILE NOT end of file DOBEGIN IFIF quantity in stock is less than reorder point THEN GENERATE new orderEND IFREAD next inventory recordEND DOStructured English•Uses action verbs to describe processes•Uses nouns to describe data structures–Fields on a data file•Contains no adjectives or AdverbsSupplierInventoryD11.1UpdateInventoryAdded1.2Update InventoryUsedStock on HandQtyAddedCountsLogical DFD - Ketler’s Version Decomposition of Process 1.0ProductsAmounts UsedLogical DFDActivities 3 and 4: Generate orders & pay orderSupplier3.0GenerateOrders4.0Pay BillInventoryQty on handReorder qtyReorder pointOrderspaymentD1InvoiceSupplier3.0GenerateOrders4.0Pay BillInventoryQty on handReorder qtyReorder pointOrderspaymentD11.0UpdateInventoryAdded2.0Update InventoryUsedStock on HandQtyAddedCounts Logical DFD - Ketler’s VersionProductsAmounts UsedInventoryD1InvoiceStructured English for Process 1.0DOREAD next invoice-item-record (info from supplier)Find matching inventory-recordAdd Quantity from invoice item record to quantity in stock on inventory-recordUNTIL end of file (invoice-item from supplier)Update Inventory AddedStructured English for Process 2.0DOREAD next Stock-item-record (from stock list)FIND matching inventory-recordSUBTRACT Quantity-used from Stock-item-record from quantity in stock on inventory-recordUNTIL end of file (stock list)Update Inventory UsedStructured English for Process 3.0DOREAD next Inventory RecordBEGIN IFIf Quantity in stock is less than reorder point THEN GENERATE OrderEND IFUNTIL end of file (Inventory)Generate OrdersStructured English for Process 4.0READ Today’s DateDOSORT invoice records (from supplier) by DateREAD next Invoice record (from supplier)BEGIN IFIf Date is 30 days or greater than Today’s Date THEN GENERATE PaymentsEND IFUNTIL end of file (Invoice – from supplier)Generate