12.1

APPRAISE SYSTEM BUILDING ALTERNATIVESAPPRAISE SYSTEM BUILDING ALTERNATIVES COMPARE STRENGTHS, WEAKNESSES OF APPROACHESCOMPARE STRENGTHS, WEAKNESSES OF APPROACHES ASSESS SOLUTIONS TO PROBLEMS CREATED BY APPROACHESASSESS SOLUTIONS TO PROBLEMS CREATED BY APPROACHES DESCRIBE TOOLS, METHODOLOGIES OF SYSTEMS DEVELOPMENTDESCRIBE TOOLS, METHODOLOGIES OF SYSTEMS DEVELOPMENT* LEARNING OBJECTIVES 12.2

MANAGEMENT CHALLENGES TRADITIONAL SYSTEMS LIFECYCLETRADITIONAL SYSTEMS LIFECYCLE ALTERNATIVE SYSTEM-BUILDING APPROACHESALTERNATIVE SYSTEM-BUILDING APPROACHES SYSTEM-BUILDING METHODOLOGIES & TOOLSSYSTEM-BUILDING METHODOLOGIES & TOOLS* 12.3

SYSTEM LIFECYCLE PROJECT DEFINITION: Is there a problem? Can it be solved with a project?PROJECT DEFINITION: Is there a problem? Can it be solved with a project? SYSTEM STUDY: Analyze problems in existing systems; define objectives evaluate alternativesSYSTEM STUDY: Analyze problems in existing systems; define objectives evaluate alternatives DESIGN: Logical & physical specifications for systems solutionDESIGN: Logical & physical specifications for systems solution PROGRAMMING: Develop software codePROGRAMMING: Develop software code* 12.4

SYSTEM LIFECYCLE INSTALLATION: Construct, test, train, convert to new systemINSTALLATION: Construct, test, train, convert to new system POSTINSTALLATION: On-going evaluation, modifications for improvement to meet new requirementsPOSTINSTALLATION: On-going evaluation, modifications for improvement to meet new requirements NECESSARY FOR LARGE, COMPLEX SYSTEMS & PROJECTS NECESSARY FOR LARGE, COMPLEX SYSTEMS & PROJECTS* 12.5

SYSTEM LIFECYCLE CAN BE COSTLY, TIME CONSUMINGCAN BE COSTLY, TIME CONSUMING MAY ENCOURAGE FREEZING SPECIFICATIONS EARLY IN DEVELOPMENTMAY ENCOURAGE FREEZING SPECIFICATIONS EARLY IN DEVELOPMENT MAY NOT BE SUITABLE FOR SMALL, LESS STRUCTURED SYSTEMSMAY NOT BE SUITABLE FOR SMALL, LESS STRUCTURED SYSTEMS* 12.6

ALTERNATIVE SYSTEM- BUILDING APPROACHES PROTOTYPINGPROTOTYPING APPLICATION SOFTWARE PACKAGESAPPLICATION SOFTWARE PACKAGES END-USER DEVELOPMENTEND-USER DEVELOPMENT OUTSOURCINGOUTSOURCING* 12.7

PROTOTYPING PROCESS OF BUILDING EXPERIMENTAL SYSTEM TO DEMONSTRATE, EVALUATE APPROACH; USERS REFINE NEEDS PROCESS OF BUILDING EXPERIMENTAL SYSTEM TO DEMONSTRATE, EVALUATE APPROACH; USERS REFINE NEEDS PROTOTYPE: Preliminary working version of information system for demonstration, evaluation purposesPROTOTYPE: Preliminary working version of information system for demonstration, evaluation purposes ITERATIVE PROCESSITERATIVE PROCESS* 12.8

STEPS IN PROTOTYPING 1. IDENTIFY USER’S REQUIREMENTS 2, DEVELOP PROTOTYPE 3, USE PROTOTYPE 4. REVISE & ENHANCE PROTOTYPE BEST FOR DESIGN OF END-USER INTERFACE: How end-user interacts with system BEST FOR DESIGN OF END-USER INTERFACE: How end-user interacts with system* 12.9

APPLICATION SOFTWARE PACKAGES PREWRITTEN, PRECODED APPLICATION SOFTWARE, COMMERCIALLY AVAILABLE FOR SALE OR LEASE PREWRITTEN, PRECODED APPLICATION SOFTWARE, COMMERCIALLY AVAILABLE FOR SALE OR LEASE GEARED TO COMMON REQUIREMENTSGEARED TO COMMON REQUIREMENTS CUSTOMIZATION: Modification of software to meet organization’s needsCUSTOMIZATION: Modification of software to meet organization’s needs MUST WEIGH COSTS / BENEFITSMUST WEIGH COSTS / BENEFITS* 12.10

SELECTED EXAMPLES OF APPLICATION PROGRAMS ACCOUNTS RECEIVABLE; BOND & STOCK MANAGEMENT; COMPUTER-AIDED DESIGN (CAD) ; DOCUMENT IMAGING; E- MAIL; ENTERPRISERESOURCE PLANNING (ERP); GROUPWARE; HEALTH CARE; HOTELMANAGEMENT; INTERNET TELEPHONE; INVENTORY CONTROL; JOB COSTING; LIBRARY SYSTEMS; LIFE INSURANCE; MAILING LABELS; MATHEMATICAL / STATISTICAL MODELING; ORDER PROCESSING; PAYROLL; PROCESS CONTROL;TAX ACCOUNTING; WEB BROWSER; WORD PROCESSING ACCOUNTS RECEIVABLE; BOND & STOCK MANAGEMENT; COMPUTER-AIDED DESIGN (CAD) ; DOCUMENT IMAGING; E- MAIL; ENTERPRISE.RESOURCE PLANNING (ERP); GROUPWARE; HEALTH CARE; HOTEL.MANAGEMENT; INTERNET TELEPHONE; INVENTORY CONTROL; JOB COSTING; LIBRARY SYSTEMS; LIFE INSURANCE; MAILING LABELS; MATHEMATICAL / STATISTICAL MODELING; ORDER PROCESSING; PAYROLL; PROCESS CONTROL;TAX ACCOUNTING; WEB BROWSER; WORD PROCESSING* 12.11

CUSTOMIZATION MODIFYING SOFTWARE PACKAGE TO MEET ORGANIZATION’S UNIQUE REQUIREMENTS WITHOUT DESTROYING INTEGRITY OF PACKAGE RAISES DEVELOPMENT COSTS * 12.12

% LINES OF CODE CONVERTED TOTAL IMPLEMENTATION COSTS EFFECTS OF CUSTOMIZING SOFTWARE ON TOTAL IMPLEMENTATION COSTS 12.13

DESCRIPTION (PRESENT, PROPOSED)DESCRIPTION (PRESENT, PROPOSED) RELIABILITYRELIABILITY BACKUPBACKUP SERVICESSERVICES SYSTEM SPECIFICATIONSSYSTEM SPECIFICATIONS CRITERIACRITERIA DEMONSTRATION (PROTOTYPE)DEMONSTRATION (PROTOTYPE) SCHEDULE (BENCH MARKS)SCHEDULE (BENCH MARKS) PRICE (PENALTIES)PRICE (PENALTIES) SPECIFIC QUESTIONSSPECIFIC QUESTIONS PROCEDURES FOR RESPONSEPROCEDURES FOR RESPONSE* REQUEST FOR PROPOSAL (RFP REQUEST FOR PROPOSAL (RFP) Source: Senn, Information Technology in Business (1995) 12.14

END-USER DEVELOPMENT END-USERS DEVELOP INFORMATION SYSTEM WITH LITTLE HELP FROM TECHNICAL SPECIALISTS USING 4th GENERATION TOOLS * 12.15

END-USER DEVELOPMENT STRENGTHS: IMPROVED REQUIREMENTS DETERMINATIONIMPROVED REQUIREMENTS DETERMINATION INCREASED USER INVOLVEMENT & SATISFACTIONINCREASED USER INVOLVEMENT & SATISFACTION REDUCED APPLICATION BACKLOGREDUCED APPLICATION BACKLOG* 12.16

END-USER DEVELOPMENT WEAKNESSES: RELATIVELY INEFFICIENTRELATIVELY INEFFICIENT SLOW TRANSACTION PROCESSINGSLOW TRANSACTION PROCESSING MAY CARRY HIGH COSTMAY CARRY HIGH COST LARGE FILES CAN DEGRADE PERFORMANCELARGE FILES CAN DEGRADE PERFORMANCE NONPROCEDURAL APPROACH MAY HAMPER LOGIC & UPDATING REQUIREMENTSNONPROCEDURAL APPROACH MAY HAMPER LOGIC & UPDATING REQUIREMENTS* 12.17

MANAGING END-USER DEVELOPMENT INFORMATION CENTER: SPECIAL FACILITY WITHIN ORGANIZATIONSPECIAL FACILITY WITHIN ORGANIZATION PROVIDES TRAINING, SUPPORT FOR END-USER-COMPUTINGPROVIDES TRAINING, SUPPORT FOR END-USER-COMPUTING* 12.18

OUTSOURCING CONTRACTING: COMPUTER CENTER OPERATIONSCOMPUTER CENTER OPERATIONS TELECOMMUNICATIONS NETWORKSTELECOMMUNICATIONS NETWORKS APPLICATION DEVELOPMENTAPPLICATION DEVELOPMENT TO EXTERNAL VENDORS TO EXTERNAL VENDORS* 12.19

OUTSOURCING WHEN TO OUTSOURCE: IF FIRM WON’T DISTINGUISH ITSELF BY DEVELOPING APPLICATIONIF FIRM WON’T DISTINGUISH ITSELF BY DEVELOPING APPLICATION PREDICTABILITY OF UNINTERRUPTED SERVICE NOT IMPORTANTPREDICTABILITY OF UNINTERRUPTED SERVICE NOT IMPORTANT IF EXISTING SYSTEM IS LIMITED, INEFFECTIVE, INFERIORIF EXISTING SYSTEM IS LIMITED, INEFFECTIVE, INFERIOR* 12.20

SYSTEM BUILDING METHODOLOGIES STRUCTURED METHODOLOGIESSTRUCTURED METHODOLOGIES OBJECT- ORIENTED SOFTWARE DEVELOPMENTOBJECT- ORIENTED SOFTWARE DEVELOPMENT COMPUTER AIDED SOFTWARE ENGINEERING (CASE)COMPUTER AIDED SOFTWARE ENGINEERING (CASE) SOFTWARE REENGINEERINGSOFTWARE REENGINEERING* 12.21

STRUCTURED METHODOLOGIES TOP DOWN, STEP BY STEP, EACH STEP BUILDS ON PREVIOUS STRUCTURED ANALYSISSTRUCTURED ANALYSIS STRUCTURED DESIGNSTRUCTURED DESIGN STRUCTURED PROGRAMMINGSTRUCTURED PROGRAMMING FLOWCHARTSFLOWCHARTS* 12.22

STRUCTURED ANALYSIS DEFINES SYSTEM INPUTS, PROCESSES, OUTPUTSDEFINES SYSTEM INPUTS, PROCESSES, OUTPUTS PARTITIONS SYSTEM INTO SUBSYSTEMS OR MODULESPARTITIONS SYSTEM INTO SUBSYSTEMS OR MODULES LOGICAL, GRAPHICAL MODEL OF INFORMATION FLOWLOGICAL, GRAPHICAL MODEL OF INFORMATION FLOW DATA FLOW DIAGRAM: Graphical display of component processes, flow of dataDATA FLOW DIAGRAM: Graphical display of component processes, flow of data* 12.23

STRUCTURED ANALYSIS DATA DICTIONARY: Controlled definitions of descriptions of all data, such as variable names & types of dataDATA DICTIONARY: Controlled definitions of descriptions of all data, such as variable names & types of data PROCESS SPECIFICATIONS: Describes logic of processes at module levelPROCESS SPECIFICATIONS: Describes logic of processes at module level* 12.26

STRUCTURED DESIGN DESIGN RULES / TECHNIQUES TO DESIGN SYSTEM, TOP DOWN IN HIERARCHICAL FASHION DESIGN RULES / TECHNIQUES TO DESIGN SYSTEM, TOP DOWN IN HIERARCHICAL FASHION STRUCTURE CHARTSTRUCTURE CHART STRUCTURED PROGRAMMINGSTRUCTURED PROGRAMMING MODULEMODULE SEQUENCE CONSTRUCTSEQUENCE CONSTRUCT SELECTION CONSTRUCTSELECTION CONSTRUCT* 12.27

STRUCTURED PROGRAMMING: DISCIPLINE TO ORGANIZE, CODE PROGRAMSDISCIPLINE TO ORGANIZE, CODE PROGRAMS SIMPLIFIES CONTROL PATHSSIMPLIFIES CONTROL PATHS EASY TO UNDERSTAND, MODIFYEASY TO UNDERSTAND, MODIFY MODULE HAS ONE INPUT, ONE OUTPUTMODULE HAS ONE INPUT, ONE OUTPUT* 12.29

STRUCTURED PROGRAMMING: MODULE: Logical unit of program. performs specific task(s)MODULE: Logical unit of program. performs specific task(s) SEQUENCE CONSTRUCT: Sequential steps or actions in program logic; streamlines flowSEQUENCE CONSTRUCT: Sequential steps or actions in program logic; streamlines flow SELECTION CONSTRUCT: IF Condition R is True THEN Action C ELSE Action DSELECTION CONSTRUCT: IF Condition R is True THEN Action C ELSE Action D ITERATION CONSTRUCT: WHILE Condition is True DO Action EITERATION CONSTRUCT: WHILE Condition is True DO Action E* 12.30

OBJECT - ORIENTED SOFTWARE DEVELOPMENT DE-EMPHASIZES PROCEDURESDE-EMPHASIZES PROCEDURES SHIFTS FOCUS FROM MODELS & DATASHIFTS FOCUS FROM MODELS & DATA TO OBJECTS, WHICH COMBINE DATA & PROCEDURESTO OBJECTS, WHICH COMBINE DATA & PROCEDURES OBJECTS REUSABLEOBJECTS REUSABLE SYSTEM: Classes; objects; relationshipsSYSTEM: Classes; objects; relationships REDUCES DEVELOPMENT TIME & COST * 12.36

COMPUTER AIDED SOFTWARE ENGINEERING (CASE) AUTOMATION OF SOFTWARE METHODOLOGIESAUTOMATION OF SOFTWARE METHODOLOGIES PRODUCES CHARTS; DIAGRAMS; SCREEN & REPORT GENERATORS; DATA DICTIONARIES; PROGRESS REPORTS; ANALYSIS; CHECKING TOOLS; CODE; DOCUMENTATIONPRODUCES CHARTS; DIAGRAMS; SCREEN & REPORT GENERATORS; DATA DICTIONARIES; PROGRESS REPORTS; ANALYSIS; CHECKING TOOLS; CODE; DOCUMENTATION* CASE 12.37

COMPUTER AIDED SOFTWARE ENGINEERING (CASE) INCREASES PRODUCTIVITY & QUALITY: ENFORCES DEVELOPMENT DISCIPLINEENFORCES DEVELOPMENT DISCIPLINE IMPROVES COMMUNICATIONIMPROVES COMMUNICATION DESIGN REPOSITORY FOR OBJECTSDESIGN REPOSITORY FOR OBJECTS AUTOMATES TEDIOUS TASKSAUTOMATES TEDIOUS TASKS AUTOMATES TESTING & CONTROLAUTOMATES TESTING & CONTROL REQUIRES ORGANIZATIONAL DISCIPLINEREQUIRES ORGANIZATIONAL DISCIPLINE* CASE 12.38

SOFTWARE REENGINEERING SALVAGES & UPGRADES AGING SOFTWARESALVAGES & UPGRADES AGING SOFTWARE DELAYS EXPENSIVE REPLACEMENTDELAYS EXPENSIVE REPLACEMENT REVERSE ENGINEERING: CONVERTING EXISTING PROGRAMS, FILES, DATABASE FOR USE IN NEW APPLICATIONSREVERSE ENGINEERING: CONVERTING EXISTING PROGRAMS, FILES, DATABASE FOR USE IN NEW APPLICATIONS* 12.39

SOFTWARE REENGINEERING REVISE DESIGN & PROGRAM SPECIFICATIONSREVISE DESIGN & PROGRAM SPECIFICATIONS FORWARD ENGINEERING: USE REVISED MATERIALS TO GENERATE NEW, STRUCTURED CODE; STRUCTURED & MAINTAINABLE SYSTEMFORWARD ENGINEERING: USE REVISED MATERIALS TO GENERATE NEW, STRUCTURED CODE; STRUCTURED & MAINTAINABLE SYSTEM* 12.40