© Prentice Hall CHAPTER 8 Basic Information Systems Concepts

© Prentice Hall SYSTEMS VIEW FRAMEWORK FOR SEEING INTERRELATIONSHIPSFRAMEWORK FOR SEEING INTERRELATIONSHIPS SYSTEM: Set of interrelated components working together to achieve common purposeSYSTEM: Set of interrelated components working together to achieve common purpose INFORMATION SYSTEM (IS): Collection of information technology, procedures, & people that captures, moves, manages, distributes data & informationINFORMATION SYSTEM (IS): Collection of information technology, procedures, & people that captures, moves, manages, distributes data & information*

© Prentice Hall SYSTEM BOUNDARY GENERAL STRUCTURE OF SYSTEM ENVIRONMENT COMPONENT 2 Interface Input 2 Interface COMPONENT 3 Input 1 STORAGE 1 COMPONENT 2 Interface Output 1

© Prentice Hall SYSTEM BOUNDARY DIVIDING LINEDIVIDING LINE PLACED BASED ON THE PURPOSE: Usually not a fixed linePLACED BASED ON THE PURPOSE: Usually not a fixed line CONTROL OR REDESIGN WITHIN THE BOUNDARYCONTROL OR REDESIGN WITHIN THE BOUNDARY ENVIRONMENT OUTSIDE THE BOUNDARYENVIRONMENT OUTSIDE THE BOUNDARY*

© Prentice Hall SYSTEM BOUNDARY WHAT CAN BE CONTROLLED: External elements are constraintsWHAT CAN BE CONTROLLED: External elements are constraints WHAT SCOPE MANAGEABLE WITHIN GIVEN TIME PERIOD: Complex systems take longer to design, modifyWHAT SCOPE MANAGEABLE WITHIN GIVEN TIME PERIOD: Complex systems take longer to design, modify WHAT IS IMPACT OF BOUNDARY CHANGE: Dynamic changes require accommodationWHAT IS IMPACT OF BOUNDARY CHANGE: Dynamic changes require accommodation*

© Prentice Hall COMPONENT DECOMPOSITION BREAK SYSTEM INTO SUBSYSTEMSBREAK SYSTEM INTO SUBSYSTEMS COMPONENTS OF SUBSYSTEM MAY FORM MORE SUBSYSTEMSCOMPONENTS OF SUBSYSTEM MAY FORM MORE SUBSYSTEMS OFTEN SUBSYSTEMS ARE EASIER TO UNDERSTAND, CREATE, MODIFYOFTEN SUBSYSTEMS ARE EASIER TO UNDERSTAND, CREATE, MODIFY*

© Prentice Hall GOALS OF HIERARCHICAL DECOMPOSITION 1. COPE WITH COMPLEXITY OF SYSTEM 2. ANALYZE OR CHANGE ONLY PART OF SYSTEM 3. DESIGN, BUILD SUBSYSTEMS AT DIFFERENT TIMES 4. DIRECT ATTENTION OF TARGET AUDIENCE 5. ALLOW COMPONENTS TO OPERATE INDEPENDENTLY *

© Prentice Hall FUNDAMENTAL COMPONENTS OF ORGANIZATION PEOPLEPEOPLE INFORMATION TECHNOLOGYINFORMATION TECHNOLOGY BUSINESS PROCESSESBUSINESS PROCESSES ORGANIZATIONAL STRUCTUREORGANIZATIONAL STRUCTURE EACH IMPACTS THE REST! *

© Prentice Hall DECISION MAKING PROCESS INTELLIGENCE: Search for needs, collect dataINTELLIGENCE: Search for needs, collect data DESIGN: Generate alternatives, test feasibilityDESIGN: Generate alternatives, test feasibility CHOICE: Select from alternativesCHOICE: Select from alternatives PERSUASION: Influencing others to accept & follow chosen solutionPERSUASION: Influencing others to accept & follow chosen solution IMPLEMENTATION: Install solution on time, within budgetIMPLEMENTATION: Install solution on time, within budget FOLLOW-UP: Monitor, modify, refineFOLLOW-UP: Monitor, modify, refine CONSTANT FEEDBACK *

© Prentice Hall BUSINESS PROCESSES A SET OF WORK ACTIVITIES & RESOURCES A SET OF WORK ACTIVITIES & RESOURCES IDENTIFYIDENTIFY EVALUATEEVALUATE REDESIGNREDESIGN USE INFORMATION TECHNOLOGY (IT) TO BREAK RULES! *

© Prentice Hall EVALUATING A PROCESS X DOES X DEFINE FIRM TO CUSTOMERS, EMPLOYEES, INVESTORS?DOES X DEFINE FIRM TO CUSTOMERS, EMPLOYEES, INVESTORS? –YES: IDENTIFY –NO: GO ON IS EXCELLING AT X CRITICAL TO BUSINESS?IS EXCELLING AT X CRITICAL TO BUSINESS? –YES: PRIORITY –NO: GO ON*

© Prentice Hall EVALUATING A PROCESS X DOES X SUPPORT OTHER PROCESSES?DOES X SUPPORT OTHER PROCESSES? –YES: BACKGROUND –NO: GO ON IS X CARRIED OUT ONLY BECAUSE IT IS LEGALLY REQUIRED?IS X CARRIED OUT ONLY BECAUSE IT IS LEGALLY REQUIRED? –YES: MANDATED –NO: FOLKLORE > ABANDON*

© Prentice Hall BUSINESS PROCESS REDESIGN* START WITH “CLEAN SLATE”START WITH “CLEAN SLATE” USE IT TO RADICALLY CHANGE PROCESSESUSE IT TO RADICALLY CHANGE PROCESSES QUESTION ASSUMPTIONS & RULESQUESTION ASSUMPTIONS & RULES ASK “WHY?”, “WHAT IF?”, “WHO SAYS SO?”, “WHAT DO CUSTOMERS THINK?”ASK “WHY?”, “WHAT IF?”, “WHO SAYS SO?”, “WHAT DO CUSTOMERS THINK?”* *Hammer, 1990

© Prentice Hall USING IT TO BREAK DYSFUNCTIONAL RULES* OLD RULE: Information can appear in only one place at one time.OLD RULE: Information can appear in only one place at one time. DISRUPTIVE TECHNOLOGY: Shared databasesDISRUPTIVE TECHNOLOGY: Shared databases NEW RULE: Information can be used simultaneously in many placesNEW RULE: Information can be used simultaneously in many places* Example #1 *Hammer & Chanmpy, 1993

© Prentice Hall OLD RULE: Only EXPERTS do complex work.OLD RULE: Only EXPERTS do complex work. DISRUPTIVE TECHNOLOGY: Expert systemsDISRUPTIVE TECHNOLOGY: Expert systems NEW RULE: Generalists can do complex work like an EXPERTNEW RULE: Generalists can do complex work like an EXPERT* *Hammer & Chanmpy, 1993 USING IT TO BREAK DYSFUNCTIONAL RULES* Example #2

© Prentice Hall OLD RULE: Field personnel need OFFICES to receive, store, retrieve, and transmit information.OLD RULE: Field personnel need OFFICES to receive, store, retrieve, and transmit information. DISRUPTIVE TECHNOLOGY: Portable and home computers, modems, and wireless data communicationDISRUPTIVE TECHNOLOGY: Portable and home computers, modems, and wireless data communication NEW RULE: Field personnel send and receive information WHEREVER they areNEW RULE: Field personnel send and receive information WHEREVER they are* *Hammer & Chanmpy, 1993 USING IT TO BREAK DYSFUNCTIONAL RULES* Example #3

© Prentice Hall PRINCIPLES FOR REDESIGNING PROCESSES* 1.ORGANIZE AROUND OUTCOMES, NOT TASKS 2.ASSIGN USERS OF OUTPUT TO PERFORM PROCESS 3.INTEGRATE INFORMATION PROCESSING INTO WORK THAT PRODUCES INFORMATION * *Hammer, 1990

© Prentice Hall PRINCIPLES FOR REDESIGNING PROCESSES* 4.CREATE VIRTUAL ENTERPRISE BY TREATING GEOGRAPHICALLY DISTRIBUTED RESOURCES AS THOUGH THEY WERE CENTRALIZED 5.LINK PARALLEL ACTIVITIES INSTEAD OF INTEGRATING THEIR RESULTS * *Hammer, 1990

© Prentice Hall PRINCIPLES FOR REDESIGNING PROCESSES* 6.HAVE PEOPLE WHO DO WORK MAKE DECISIONS, MONITOR PROCESS BY BUILT-IN CONTROLS * *Hammer, 1990

© Prentice Hall INFORMATION SYSTEMS LIFE CYCLE DEFINITION PHASE: End-users & analysts conduct analysisDEFINITION PHASE: End-users & analysts conduct analysis CONSTRUCTION: Use of structured techniques, system development methodologyCONSTRUCTION: Use of structured techniques, system development methodology IMPLEMENTATION: Plan, test, train, accept, monitorIMPLEMENTATION: Plan, test, train, accept, monitor*

© Prentice Hall LOGIC TO-BE MODEL SYMBOLS ELEMENT SENDING OR RECEIVING DATA. NAMES ARE NOUN LABELS DATA IN MOTION BETWEEN ELEMENTS. NAMES ARE NOUNS OR NUMBERS PROCESSES WITH INPUT & OUTPUT. NAMES ARE VERB PHRASES & NUMBERS DATA STORE WITH INPUT & OUTPUT. NAMES ARE NOUNS & NUMBERS *

© Prentice Hall LOGIC TO-BE MODEL PROCESSES IDENTIFY ENTITIES THAT SUPPLY, USE SYSTEM INFORMATIONIDENTIFY ENTITIES THAT SUPPLY, USE SYSTEM INFORMATION DISTINGUISH PROCESSES FROM DATA THEY USE OR PRODUCEDISTINGUISH PROCESSES FROM DATA THEY USE OR PRODUCE EXPLICATES RULES AFFECTING CHANGING DATA TO INFORMATIONEXPLICATES RULES AFFECTING CHANGING DATA TO INFORMATION IDENTIFY LOGICAL RELATIONSHIPSIDENTIFY LOGICAL RELATIONSHIPS PINPOINT DUPLICATE STORAGE, MOVEMENT OF DATAPINPOINT DUPLICATE STORAGE, MOVEMENT OF DATA*

© Prentice Hall WORK PROCESS FLOW SYMBOLS : DOCUMENT DATABASE ON-LINE DISPLAY TELECOMMUNICATIONS LINK INPUT/OUTPUT PROCESS MAGNETIC TAPE PUNCHED CARD MANUAL OPERATION ON-LINE STORAGE ON-LINE INPUT

© Prentice Hall PROGRAM FLOWCHART SYMBOLS: BEGIN OR END DIRECTION PROCESS DECISION INPUT OR OUTPUT SUBROUTINE MANUAL OPERATION CONNECTOR

© Prentice Hall OBJECT-ORIENTED TECHNIQUES KEY IDEA: Work with reusable objects to speed up development!KEY IDEA: Work with reusable objects to speed up development! TWO PRINCIPLES: ENCAPSULATION: Store data and related operations together within objectsENCAPSULATION: Store data and related operations together within objects INHERITANCE: Share common characteristics between classes of objectsINHERITANCE: Share common characteristics between classes of objects*

© Prentice Hall OBJECT-ORIENTED APPROACH DEFINE TASK: Search library of existing objects useful to taskDEFINE TASK: Search library of existing objects useful to task PROCESS: Create bare-bones prototype, test, provide critical feedback, repeat & refinePROCESS: Create bare-bones prototype, test, provide critical feedback, repeat & refine ELAPSED TIME: Can be weeksELAPSED TIME: Can be weeks*

© Prentice Hall IT-RELATED RISKS ORGANIZATIONAL RISKS: From changes in environmentORGANIZATIONAL RISKS: From changes in environment PERSONNEL RISKS: From loss of expertise, system use (or non-use)PERSONNEL RISKS: From loss of expertise, system use (or non-use) SYSTEM PROJECT RISKS: From project management deficienciesSYSTEM PROJECT RISKS: From project management deficiencies EXTERNAL SECURITY RISKS: Criminal acts, natural disastersEXTERNAL SECURITY RISKS: Criminal acts, natural disasters*

© Prentice Hall LIFE CYCLE CONTROLS DEFINITION & CONSTRUCTION:DEFINITION & CONSTRUCTION: –Methodology standards –Validation rules & calculations –System testing IMPLEMENTATION:IMPLEMENTATION: –Security –Backup & recovery –Auditing Roles*

© Prentice Hall CHAPTER 8 Basic Information Systems Concepts