10.1 CHAPTER 10. APPROACHES TO SYSTEM BUILDING. 10.2 APPRAISE SYSTEM BUILDING ALTERNATIVESAPPRAISE...

10.10.11

DATA FLOW DIAGRAMDATA FLOW DIAGRAM::

GENERATE BILL

CUSTOMER

GENERATE BALANCE

GENERATE REPORT

MANAGER

PAYMENTFILE

CUSTOMERFILE

CHAPTER 10.

CHAPTER 10.

APPROACHES TO SYSTEM


BUILDINGBUILDING

CHAPTER 10.

CHAPTER 10.



BUILDINGBUILDING

10.10.22

• APPRAISE SYSTEM BUILDING APPRAISE SYSTEM BUILDING ALTERNATIVESALTERNATIVES

• COMPARE STRENGTHS, WEAKNESSES COMPARE STRENGTHS, WEAKNESSES OF APPROACHESOF APPROACHES

• ASSESS SOLUTIONS TO PROBLEMS ASSESS SOLUTIONS TO PROBLEMS CREATED BY APPROACHESCREATED BY APPROACHES

• DESCRIBE TOOLS, METHODOLOGIES OF DESCRIBE TOOLS, METHODOLOGIES OF SYSTEMS DEVELOPMENTSYSTEMS DEVELOPMENT

**

LEARNING OBJECTIVESLEARNING OBJECTIVES

10.10.33

MANAGEMENT CHALLENGESMANAGEMENT CHALLENGES

• TRADITIONAL SYSTEMS LIFECYCLETRADITIONAL SYSTEMS LIFECYCLE

• ALTERNATIVE SYSTEM-BUILDING ALTERNATIVE SYSTEM-BUILDING APPROACHESAPPROACHES

• SYSTEM-BUILDING SYSTEM-BUILDING METHODOLOGIES & TOOLSMETHODOLOGIES & TOOLS

**

10.10.44

SYSTEM LIFECYCLESYSTEM LIFECYCLE

• PROJECT DEFINITION:PROJECT DEFINITION: Is there a Is there a problem? Can it be solved with a project?problem? Can it be solved with a project?

• SYSTEM STUDY:SYSTEM STUDY: Analyze problems in Analyze problems in existing systems; define objectives existing systems; define objectives evaluate alternativesevaluate alternatives

• DESIGN:DESIGN: Logical & physical specifications Logical & physical specifications for systems solutionfor systems solution

• PROGRAMMING:PROGRAMMING: Develop software codeDevelop software code

**

10.10.55


• INSTALLATION:INSTALLATION: Construct, test, train, Construct, test, train, convert to new systemconvert to new system

• POSTINSTALLATION:POSTINSTALLATION: On-going On-going evaluation, modifications for improvement evaluation, modifications for improvement to meet new requirementsto meet new requirements

NECESSARY FOR LARGE, COMPLEX NECESSARY FOR LARGE, COMPLEX SYSTEMS & PROJECTSSYSTEMS & PROJECTS

**

10.10.66


• CAN BE COSTLY, TIME CONSUMINGCAN BE COSTLY, TIME CONSUMING• MAY ENCOURAGE FREEZING MAY ENCOURAGE FREEZING

SPECIFICATIONS EARLY IN SPECIFICATIONS EARLY IN DEVELOPMENTDEVELOPMENT

• MAY NOT BE SUITABLE FOR SMALL, MAY NOT BE SUITABLE FOR SMALL, LESS STRUCTURED SYSTEMSLESS STRUCTURED SYSTEMS

**

10.10.77

ALTERNATIVE SYSTEM-ALTERNATIVE SYSTEM-BUILDING APPROACHESBUILDING APPROACHES

• PROTOTYPINGPROTOTYPING

• APPLICATION SOFTWARE APPLICATION SOFTWARE PACKAGESPACKAGES

• END-USER DEVELOPMENTEND-USER DEVELOPMENT

• OUTSOURCINGOUTSOURCING

**

10.10.88

PROTOTYPINGPROTOTYPING PROCESS OF BUILDING EXPERIMENTAL PROCESS OF BUILDING EXPERIMENTAL

SYSTEM TO DEMONSTRATE, EVALUATE SYSTEM TO DEMONSTRATE, EVALUATE APPROACH; USERS REFINE NEEDSAPPROACH; USERS REFINE NEEDS

• PROTOTYPE:PROTOTYPE: Preliminary working Preliminary working version of information system for version of information system for demonstration, evaluation purposesdemonstration, evaluation purposes

• ITERATIVE PROCESSITERATIVE PROCESS

**

10.10.99

STEPS INSTEPS IN PROTOTYPING PROTOTYPING

1. IDENTIFY USER’S REQUIREMENTS1. IDENTIFY USER’S REQUIREMENTS

2. DEVELOP PROTOTYPE2. DEVELOP PROTOTYPE

3. USE PROTOTYPE3. USE PROTOTYPE

4. REVISE & ENHANCE PROTOTYPE4. REVISE & ENHANCE PROTOTYPE

BEST FOR DESIGN OF END-USER BEST FOR DESIGN OF END-USER INTERFACE:INTERFACE: How end-user interacts How end-user interacts with systemwith system

**

10.10.1010

APPLICATION SOFTWARE APPLICATION SOFTWARE PACKAGESPACKAGES

PREWRITTEN, PRECODED APPLICATION PREWRITTEN, PRECODED APPLICATION SOFTWARE, COMMERCIALLY SOFTWARE, COMMERCIALLY AVAILABLE FOR SALE OR LEASEAVAILABLE FOR SALE OR LEASE

• GEARED TO GEARED TO COMMON REQUIREMENTSCOMMON REQUIREMENTS• CUSTOMIZATION:CUSTOMIZATION: Modification of Modification of

software to meet organization’s needssoftware to meet organization’s needs• MUST WEIGH MUST WEIGH COSTS / BENEFITSCOSTS / BENEFITS

**

10.10.1111

SELECTED EXAMPLES OF SELECTED EXAMPLES OF APPLICATION PROGRAMSAPPLICATION PROGRAMS

ACCOUNTS RECEIVABLE; BOND & STOCK ACCOUNTS RECEIVABLE; BOND & STOCK MANAGEMENT; MANAGEMENT; COMPUTER-AIDED DESIGN (CAD) ; COMPUTER-AIDED DESIGN (CAD) ; DOCUMENT IMAGING;DOCUMENT IMAGING; E- MAIL; E- MAIL; ENTERPRISEENTERPRISE.RESOURCE PLANNING (ERP); RESOURCE PLANNING (ERP); GROUPWARE; GROUPWARE; HEALTH CARE; HEALTH CARE; HOTELHOTEL.MANAGEMENT; MANAGEMENT; INTERNET TELEPHONE; INTERNET TELEPHONE; INVENTORY CONTROL; INVENTORY CONTROL; JOB JOB COSTING; COSTING; LIBRARY SYSTEMS; LIBRARY SYSTEMS; LIFE INSURANCE; LIFE INSURANCE; MAILING LABELS; MAILING LABELS; MATHEMATICAL / STATISTICAL MATHEMATICAL / STATISTICAL MODELING; MODELING; ORDER PROCESSING; ORDER PROCESSING; PAYROLL; PAYROLL; PROCESS CONTROL;TAX ACCOUNTING; PROCESS CONTROL;TAX ACCOUNTING;

WEB BROWSER;WEB BROWSER; WORD PROCESSINGWORD PROCESSING

**

10.10.1212

CUSTOMIZATIONCUSTOMIZATION

MODIFYING SOFTWARE PACKAGE MODIFYING SOFTWARE PACKAGE

TO MEET ORGANIZATION’S UNIQUE TO MEET ORGANIZATION’S UNIQUE REQUIREMENTSREQUIREMENTS

WITHOUT DESTROYING INTEGRITY WITHOUT DESTROYING INTEGRITY OF PACKAGEOF PACKAGE

RAISES DEVELOPMENT COSTSRAISES DEVELOPMENT COSTS

**

10.10.1313

EFFECTS OF CUSTOMIZING SOFTWARE ON EFFECTS OF CUSTOMIZING SOFTWARE ON TOTAL IMPLEMENTATION COSTSTOTAL IMPLEMENTATION COSTS

0

2

4

6

8

10

0.5 1 2 3 4 5

% LINES OF CODE CONVERTED% LINES OF CODE CONVERTED

TO

TA

L IM

PL

EM

EN

TA

TIO

NT

OT

AL

IMP

LE

ME

NT

AT

ION

C

OS

TS

CO

ST

S

10.10.1414

• DESCRIPTION (PRESENT, PROPOSED)DESCRIPTION (PRESENT, PROPOSED)• RELIABILITYRELIABILITY• BACKUPBACKUP• SERVICESSERVICES• SYSTEM SPECIFICATIONSSYSTEM SPECIFICATIONS• CRITERIACRITERIA• DEMONSTRATION (PROTOTYPE)DEMONSTRATION (PROTOTYPE)• SCHEDULE (BENCHMARKS)SCHEDULE (BENCHMARKS)• PRICE (PENALTIES)PRICE (PENALTIES)• SPECIFIC QUESTIONSSPECIFIC QUESTIONS• PROCEDURES FOR RESPONSEPROCEDURES FOR RESPONSE

**

REQUEST FOR PROPOSAL (RFPREQUEST FOR PROPOSAL (RFP)

Source: Senn, Information Technology in Business (1995)

10.10.1515

END-USER DEVELOPMENTEND-USER DEVELOPMENT

END-USERS DEVELOP INFORMATION END-USERS DEVELOP INFORMATION SYSTEMSYSTEM

WITH LITTLE HELP FROM WITH LITTLE HELP FROM

TECHNICAL SPECIALISTSTECHNICAL SPECIALISTS

USING 4th GENERATION TOOLSUSING 4th GENERATION TOOLS

**

10.10.1616


STRENGTHS:STRENGTHS:• IMPROVED REQUIREMENTS IMPROVED REQUIREMENTS

DETERMINATIONDETERMINATION• INCREASED USER INVOLVEMENT & INCREASED USER INVOLVEMENT &

SATISFACTIONSATISFACTION• REDUCED APPLICATION BACKLOGREDUCED APPLICATION BACKLOG

**

10.10.1717


WEAKNESSES: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 APPROACHNONPROCEDURAL APPROACH MAY MAY

HAMPER LOGIC & HAMPER LOGIC & UPDATING UPDATING REQUIREMENTSREQUIREMENTS

**

10.10.1818

MANAGING END-USER MANAGING END-USER DEVELOPMENTDEVELOPMENT

INFORMATION CENTER:INFORMATION CENTER:• SPECIAL FACILITY WITHIN SPECIAL FACILITY WITHIN

ORGANIZATIONORGANIZATION• PROVIDES TRAINING, SUPPORT FOR PROVIDES TRAINING, SUPPORT FOR

END-USER-COMPUTINGEND-USER-COMPUTING

**

10.10.1919

OUTSOURCINGOUTSOURCING

CONTRACTING:CONTRACTING:• COMPUTER CENTER OPERATIONSCOMPUTER CENTER OPERATIONS• TELECOMMUNICATIONS NETWORKSTELECOMMUNICATIONS NETWORKS• APPLICATION DEVELOPMENTAPPLICATION DEVELOPMENT

TO EXTERNAL VENDORSTO EXTERNAL VENDORS

**

10.10.2020

OUTSOURCINGOUTSOURCING

WHEN TO OUTSOURCE:WHEN TO OUTSOURCE:• IF FIRM WON’T DISTINGUISH ITSELF BY IF FIRM WON’T DISTINGUISH ITSELF BY

DEVELOPING APPLICATIONDEVELOPING APPLICATION• IF PREDICTABILITY OF UNINTERRUPTED IF PREDICTABILITY OF UNINTERRUPTED

SERVICE NOT IMPORTANTSERVICE NOT IMPORTANT• IF EXISTING SYSTEM IS IF EXISTING SYSTEM IS

LIMITED, INEFFECTIVE, LIMITED, INEFFECTIVE, INFERIORINFERIOR

**

10.10.2121

SYSTEM BUILDING APPROACHESSYSTEM BUILDING APPROACHES

• STRUCTURED METHODOLOGIESSTRUCTURED METHODOLOGIES

• OBJECT- ORIENTED SOFTWARE OBJECT- ORIENTED SOFTWARE DEVELOPMENTDEVELOPMENT

• COMPUTER AIDED SOFTWARE COMPUTER AIDED SOFTWARE ENGINEERING (CASE)ENGINEERING (CASE)

• SOFTWARE REENGINEERINGSOFTWARE REENGINEERING

**

10.10.2222

STRUCTURED STRUCTURED METHODOLOGIESMETHODOLOGIES

TOP DOWN, STEP BY STEP, EACH TOP DOWN, STEP BY STEP, EACH STEP BUILDS ON PREVIOUSSTEP BUILDS ON PREVIOUS

• STRUCTURED ANALYSISSTRUCTURED ANALYSIS

• STRUCTURED DESIGNSTRUCTURED DESIGN

• STRUCTURED PROGRAMMINGSTRUCTURED PROGRAMMING

• FLOWCHARTSFLOWCHARTS

**

10.10.2323

STRUCTURED ANALYSISSTRUCTURED ANALYSIS

• DEFINES SYSTEM INPUTS, PROCESSES, DEFINES SYSTEM INPUTS, PROCESSES, OUTPUTSOUTPUTS

• PARTITIONS SYSTEM INTO SUBSYSTEMS PARTITIONS SYSTEM INTO SUBSYSTEMS OR MODULESOR MODULES

• LOGICAL, GRAPHICAL MODEL OF LOGICAL, GRAPHICAL MODEL OF INFORMATION FLOWINFORMATION FLOW

• DATA FLOW DIAGRAM:DATA FLOW DIAGRAM: Graphical display Graphical display of component processes, flow of dataof component processes, flow of data

**

10.10.2424

SYMBOLS FOR DATA FLOW DIAGRAMS (DFD):SYMBOLS FOR DATA FLOW DIAGRAMS (DFD):

DATA FLOWDATA FLOW

PROCESSPROCESS

SOURCESOURCEOR SINKOR SINK

FILEFILE

10.10.2525

GENERATE BILL

CUSTOMER

GENERATE BALANCE

GENERATE REPORT

MANAGER

PAYMENTFILE

CUSTOMERFILE

DATA FLOW DIAGRAM:DATA FLOW DIAGRAM:

10.10.2626

• DATA DICTIONARY:DATA DICTIONARY: Controlled definitions Controlled definitions of descriptions of all data, such as of descriptions of all data, such as variable names & types of datavariable names & types of data

• PROCESS SPECIFICATIONS:PROCESS SPECIFICATIONS: Describes Describes logic of processes at module level logic of processes at module level

**

STRUCTURED ANALYSISSTRUCTURED ANALYSIS

10.10.2727

STRUCTURED DESIGNSTRUCTURED DESIGN

DESIGN RULES / TECHNIQUES TO DESIGN DESIGN RULES / TECHNIQUES TO DESIGN SYSTEM, TOP DOWN IN HIERARCHICAL SYSTEM, TOP DOWN IN HIERARCHICAL

FASHIONFASHION• STRUCTURE CHARTSTRUCTURE CHART• STRUCTURED PROGRAMMINGSTRUCTURED PROGRAMMING• MODULEMODULE• SEQUENCE CONSTRUCTSEQUENCE CONSTRUCT• SELECTION CONSTRUCTSELECTION CONSTRUCT

**

10.10.2828

HIGH LEVEL STRUCTURE CHART:HIGH LEVEL STRUCTURE CHART:HIGH LEVEL STRUCTURE CHART:

CALCULATE

GROSS PAY

CALCULATE

NET PAY

CALCULATE

PAY

PROCESS

PAYROLL

UPDATE

MASTER FILE

GET VALID

INPUTS

WRITE

OUTPUTS

GET

INPUTS

VALIDATE

INPUTS

WRITE

OUTPUTS

(WHITE BOXES ARE MODULES)(WHITE BOXES ARE MODULES)

10.10.2929

STRUCTURED PROGRAMMING:STRUCTURED PROGRAMMING:

• DISCIPLINE TO ORGANIZE, CODE DISCIPLINE TO ORGANIZE, CODE PROGRAMSPROGRAMS

• SIMPLIFIES CONTROL PATHSSIMPLIFIES CONTROL PATHS

• EASY TO UNDERSTAND, MODIFYEASY TO UNDERSTAND, MODIFY

• MODULE HAS ONE INPUT, ONE MODULE HAS ONE INPUT, ONE OUTPUTOUTPUT

**

10.10.3030

STRUCTURED PROGRAMMING:STRUCTURED PROGRAMMING:

• MODULE:MODULE: Logical unit of program. performs Logical unit of program. performs specific task(s)specific task(s)

• SEQUENCE CONSTRUCT:SEQUENCE CONSTRUCT: Sequential steps Sequential steps or actions in program logic; streamlines flowor actions in program logic; streamlines flow

• SELECTION CONSTRUCT:SELECTION CONSTRUCT: IF condition R is IF condition R is True THEN action C ELSE action DTrue THEN action C ELSE action D

• ITERATION CONSTRUCT:ITERATION CONSTRUCT: WHILE Condition WHILE Condition is True DO action Eis True DO action E

**

10.10.3131

PROGRAM FLOWCHART SYMBOLS:PROGRAM FLOWCHART SYMBOLS:

BEGIN OREND

DIRECTION

PROCESS

DECISION

INPUT OROUTPUT

SUBROUTINE

MANUALOPERATION

CONNECTOR

10.10.3232

PROGRAM FLOWCHART:PROGRAM FLOWCHART:1

END

REPORT

MORE?2

PRINT

1

2START

READ

>$10,000

<$10,000

PROCESS A

PROCESS B

10.10.3333

PROGRAM FLOWCHART:PROGRAM FLOWCHART:PROCESS A

PROCESS B

SEQUENCESEQUENCE

PROCESS E

S

TRUE

ITERATIONITERATION

PROCESS CPROCESS D

R

TRUE

SELECTIONSELECTION

10.10.3434

SYSTEM FLOWCHART SYMBOLS:SYSTEM FLOWCHART SYMBOLS:

DOCUMENT

DATABASE

ON-LINE DISPLAY TELECOMMUNICATIONS LINK

INPUT/OUTPUT PROCESS MAGNETIC TAPE

PUNCHED CARD MANUAL OPERATION ON-LINE STORAGE

ON-LINE INPUT

10.10.3535

LOAD & VALIDATE

COMPARE & UPDATE

VALID TRANS-

ACTIONS

PAYROLL SYSTEM

TIME CARDS

HUMAN RESOURCES

DATA

PAYROLL MASTER

UPDATED PAYROLL

MASTER

DIRECT DEPOSITS

GENERAL LEDGER

PAYROLL REPORTS &

CHECKS

PAYROLL MASTER

SYSTEM FLOWCHART:SYSTEM FLOWCHART:

10.10.3636

OBJECT - ORIENTED SOFTWARE OBJECT - ORIENTED SOFTWARE DEVELOPMENTDEVELOPMENT

• DE-EMPHASIZES PROCEDURESDE-EMPHASIZES PROCEDURES• SHIFTS FOCUS FROM MODELS & DATASHIFTS FOCUS FROM MODELS & DATA• TOTO OBJECTS, WHICH COMBINE DATA & OBJECTS, WHICH COMBINE DATA &

PROCEDURESPROCEDURES• OBJECTS REUSABLEOBJECTS REUSABLE• SYSTEM: Classes; objects; relationshipsSYSTEM: Classes; objects; relationships

REDUCES DEVELOPMENT TIME & COSTREDUCES DEVELOPMENT TIME & COST

**

10.10.3737

COMPUTER AIDED SOFTWARE COMPUTER AIDED SOFTWARE ENGINEERING ENGINEERING (CASE)(CASE)

• AUTOMATION OF SOFTWARE AUTOMATION OF SOFTWARE METHODOLOGIESMETHODOLOGIES

• PRODUCES CHARTS; DIAGRAMS; PRODUCES CHARTS; DIAGRAMS; SCREEN & REPORT GENERATORS; SCREEN & REPORT GENERATORS; DATA DICTIONARIES; PROGRESS DATA DICTIONARIES; PROGRESS REPORTS; ANALYSIS; CHECKING REPORTS; ANALYSIS; CHECKING TOOLS; CODE; DOCUMENTATIONTOOLS; CODE; DOCUMENTATION

**

CASECASE

10.10.3838

INCREASES PRODUCTIVITY & QUALITY: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

**

COMPUTER AIDED SOFTWARE COMPUTER AIDED SOFTWARE ENGINEERING ENGINEERING (CASE)(CASE)

CASECASE

10.10.3939

RAPID APPLICATION DEVELOPMENT RAPID APPLICATION DEVELOPMENT (RAD)(RAD)

DEVELOP SYSTEM RAPIDLY:DEVELOP SYSTEM RAPIDLY:

• PROTOTYPINGPROTOTYPING

• 4th GENERATION TOOLS4th GENERATION TOOLS

• CLOSE TEAMWORK AMONG USERS CLOSE TEAMWORK AMONG USERS & SPECIALISTS& SPECIALISTS

**

10.10.4040

SOFTWARE REENGINEERINGSOFTWARE REENGINEERING

• SALVAGES & UPGRADES AGING SALVAGES & UPGRADES AGING SOFTWARESOFTWARE

• DELAYS EXPENSIVE REPLACEMENTDELAYS EXPENSIVE REPLACEMENT• REVERSE ENGINEERING:REVERSE ENGINEERING: Converting Converting

existing programs, files, database for use existing programs, files, database for use in new applicationsin new applications

**

10.10.4141

SOFTWARE REENGINEERINGSOFTWARE REENGINEERING

• REVISE DESIGN & PROGRAM REVISE DESIGN & PROGRAM SPECIFICATIONSSPECIFICATIONS

• FORWARD ENGINEERING:FORWARD ENGINEERING: Use revised Use revised materials to generate new, structured materials to generate new, structured code; structured & maintainable systemcode; structured & maintainable system

**

10.10.4242

Connect to the INTERNETConnect to the INTERNET

Laudon/Laudon Web site: http://www.prenhall.com/laudon

Additional Internet Resources related to this chapter:http://www.sap.comhttp://www.yourdon.com/index.htmhttp://www.erpassist.com http://www.togethersoft.comhttp://www.cio.com/forums/erp http://www.spr.comhttp://www.erpsupersite.com http://www.rational.comhttp://osiris.sunderland.ac.uk/sst/casehome.htmlhttp://www.eiffel.comhttp://www.brint.comhttp://www.reengineering.comhttp://www.bpr.comhttp://bprc.warwick.ac.ukhttp://www.cne.gmu.edu

© 2001 Laudon & Laudon, Essentials of Management Information Systems 4/e

10.10.4343

DATA FLOW DIAGRAMDATA FLOW DIAGRAM::

GENERATE BILL

CUSTOMER

GENERATE BALANCE

GENERATE REPORT

MANAGER

PAYMENTFILE

CUSTOMERFILE

CHAPTER 10.

CHAPTER 10.



BUILDINGBUILDING

CHAPTER 10.

CHAPTER 10.



BUILDINGBUILDING

10.1 CHAPTER 10. APPROACHES TO SYSTEM BUILDING. 10.2 APPRAISE SYSTEM BUILDING ALTERNATIVESAPPRAISE...

Documents

Transcript of 10.1 CHAPTER 10. APPROACHES TO SYSTEM BUILDING. 10.2 APPRAISE SYSTEM BUILDING ALTERNATIVESAPPRAISE...