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					                 DIAGRAM:
       DATA FLOW DIAGRAM:

                             GENERATE
                              BALANCE
       GENERATE
         BILL

                  CUSTOMER              PAYMENT
                  FILE                  FILE

                             GENERATE
                              REPORT

       CUSTOMER



                                              MANAGER




12.1
  LEARNING OBJECTIVES
  • APPRAISE SYSTEM BUILDING
     ALTERNATIVES
  • COMPARE STRENGTHS,
     WEAKNESSES OF APPROACHES
  • ASSESS SOLUTIONS TO PROBLEMS
     CREATED BY APPROACHES
  • DESCRIBE TOOLS,
     METHODOLOGIES OF
       SYSTEMS DEVELOPMENT
12.2
                  *
  MANAGEMENT CHALLENGES

 • TRADITIONAL SYSTEMS LIFECYCLE
 • ALTERNATIVE SYSTEM-BUILDING
   APPROACHES
 • SYSTEM-BUILDING
   METHODOLOGIES & TOOLS
                 *


12.3
       SYSTEM LIFECYCLE
 • PROJECT DEFINITION: Is there a
   problem? Can it be solved with a project?
 • SYSTEM STUDY: Analyze problems in
   existing systems; define objectives
   evaluate alternatives
 • DESIGN: Logical & physical specifications
   for systems solution
 • PROGRAMMING: Develop software code
                       *
12.4
       SYSTEM LIFECYCLE
 • INSTALLATION: Construct, test, train,
   convert to new system
 • POSTINSTALLATION: On-going
   evaluation, modifications for improvement
   to meet new requirements
      NECESSARY FOR LARGE, COMPLEX
            SYSTEMS & PROJECTS
                       *

12.5
       SYSTEM LIFECYCLE
 • CAN BE COSTLY, TIME CONSUMING
 • MAY ENCOURAGE FREEZING
   SPECIFICATIONS EARLY IN
   DEVELOPMENT
 • MAY NOT BE SUITABLE FOR SMALL,
   LESS STRUCTURED SYSTEMS
                    *


12.6
       ALTERNATIVE SYSTEM-
       BUILDING APPROACHES
 • PROTOTYPING
 • APPLICATION SOFTWARE
   PACKAGES
 • END-USER DEVELOPMENT
 • OUTSOURCING
                 *


12.7
         PROTOTYPING
         PROCESS OF BUILDING
       EXPERIMENTAL SYSTEM TO
       DEMONSTRATE, EVALUATE
    APPROACH; USERS REFINE NEEDS
 • PROTOTYPE: Preliminary working
   version of information system for
   demonstration, evaluation purposes
 • ITERATIVE 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
                  *
12.9
        APPLICATION SOFTWARE
              PACKAGES
   PREWRITTEN, PRECODED APPLICATION
   SOFTWARE, COMMERCIALLY
   AVAILABLE FOR SALE OR LEASE
 • GEARED TO COMMON REQUIREMENTS
 • CUSTOMIZATION: Modification of
   software to meet organization’s needs
 • MUST WEIGH COSTS / BENEFITS
                      *

12.10
      SELECTED EXAMPLES OF
      APPLICATION PROGRAMS
           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
 EFFECTS OF CUSTOMIZING SOFTWARE ON
     TOTAL IMPLEMENTATION COSTS

                               10
        TOTAL IMPLEMENTATION




                                8

                                6
                COSTS




                                4

                                2

                                0
                                    0.5   1      2      3     4       5

                                          % LINES OF CODE CONVERTED


12.13
     REQUEST FOR PROPOSAL (RFP)
 •    DESCRIPTION (PRESENT, PROPOSED)
 •    RELIABILITY
 •    BACKUP
 •    SERVICES
 •    SYSTEM SPECIFICATIONS
 •    CRITERIA
 •    DEMONSTRATION (PROTOTYPE)
 •    SCHEDULE (BENCH MARKS)
 •    PRICE (PENALTIES)
 •    SPECIFIC QUESTIONS
 •    PROCEDURES FOR RESPONSE
12.14
                         *
          Source: Senn, Information Technology in Business (1995)
  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
   DETERMINATION
 • INCREASED USER INVOLVEMENT &
   SATISFACTION
 • REDUCED APPLICATION BACKLOG
                   *


12.16
 END-USER DEVELOPMENT
  WEAKNESSES:
  • RELATIVELY INEFFICIENT
  • SLOW TRANSACTION PROCESSING
  • MAY CARRY HIGH COST
  • LARGE FILES CAN DEGRADE
     PERFORMANCE
  • NONPROCEDURAL APPROACH
     MAY HAMPER LOGIC &
       UPDATING REQUIREMENTS
12.17                *
        MANAGING END-USER
          DEVELOPMENT
 INFORMATION CENTER:
 • SPECIAL FACILITY WITHIN
   ORGANIZATION
 • PROVIDES TRAINING, SUPPORT FOR
   END-USER-COMPUTING
                    *




12.18
        OUTSOURCING
 CONTRACTING:
 • COMPUTER CENTER OPERATIONS
 • TELECOMMUNICATIONS NETWORKS
 • APPLICATION DEVELOPMENT
   TO EXTERNAL VENDORS
                *


12.19
         OUTSOURCING
 WHEN TO OUTSOURCE:
 • IF FIRM WON’T DISTINGUISH ITSELF BY
   DEVELOPING APPLICATION
 • PREDICTABILITY OF UNINTERRUPTED
   SERVICE NOT IMPORTANT
 • IF EXISTING SYSTEM IS
       LIMITED, INEFFECTIVE,
       INFERIOR
                      *
12.20
        SYSTEM BUILDING
        METHODOLOGIES
 • STRUCTURED METHODOLOGIES
 • OBJECT- ORIENTED SOFTWARE
   DEVELOPMENT
 • COMPUTER AIDED SOFTWARE
   ENGINEERING (CASE)
 • SOFTWARE REENGINEERING
                 *
12.21
         STRUCTURED
        METHODOLOGIES
 TOP DOWN, STEP BY STEP, EACH
   STEP BUILDS ON PREVIOUS
 • STRUCTURED ANALYSIS
 • STRUCTURED DESIGN
 • STRUCTURED PROGRAMMING
 • FLOWCHARTS
                 *
12.22
        STRUCTURED ANALYSIS

 • DEFINES SYSTEM INPUTS, PROCESSES,
   OUTPUTS
 • PARTITIONS SYSTEM INTO SUBSYSTEMS
   OR MODULES
 • LOGICAL, GRAPHICAL MODEL OF
   INFORMATION FLOW
 • DATA FLOW DIAGRAM: Graphical display
   of component processes, flow of data
                     *
12.23
SYMBOLS FOR DATA FLOW DIAGRAMS (DFD):

                          DATA FLOW



                          PROCESS



                          SOURCE
                          OR SINK



                          FILE

12.24
DATA FLOW DIAGRAM:

                        GENERATE
                         BALANCE
  GENERATE
    BILL
             CUSTOMER              PAYMENT
             FILE                  FILE

                        GENERATE
                         REPORT
  CUSTOMER



                                             MANAGER




12.25
          STRUCTURED
           ANALYSIS
 • DATA DICTIONARY: Controlled definitions
   of descriptions of all data, such as
   variable names & types of data
 • PROCESS SPECIFICATIONS: Describes
   logic of processes at module level
                        *




12.26
        STRUCTURED DESIGN

        DESIGN RULES / TECHNIQUES TO
         DESIGN SYSTEM, TOP DOWN IN
           HIERARCHICAL FASHION
 •   STRUCTURE CHART
 •   STRUCTURED PROGRAMMING
 •   MODULE
 •   SEQUENCE CONSTRUCT
 •   SELECTION CONSTRUCT
                     *
12.27
        HIGH LEVEL STRUCTURE CHART:
                                      PROCESS
                                      PAYROLL




              GET VALID               CALCULATE                  WRITE
               INPUTS                    PAY                    OUTPUTS




                          CALCULATE               CALCULATE
                          GROSS PAY                NET PAY




        GET               VALIDATE                  UPDATE                 WRITE
    INPUTS                 INPUTS                 MASTER FILE             OUTPUTS


                   (WHITE BOXES ARE MODULES)
12.28
 STRUCTURED PROGRAMMING:

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

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


         INPUT/OUTPUT        PROCESS          MAGNETIC TAPE




        PUNCHED CARD      MANUAL OPERATION   ON-LINE STORAGE




          DOCUMENT
                                                DATABASE

         ON-LINE INPUT




        ON-LINE DISPLAY                  TELECOMMUNICATIONS LINK

12.31
 SYSTEM FLOWCHART:
        HUMAN
    RESOURCES DATA                                       PAYROLL
                                TIME CARDS               MASTER




                                  LOAD &
                                 VALIDATE



PAYROLL SYSTEM
                                  VALID
                                 TRANS-                PAYROLL
                                ACTIONS                MASTER




                           COMPARE &      UPDATE




         PAYROLL                                   UPDATED PAYROLL
        REPORTS &     DIRECT           GENERAL
                                                        MASTER
         CHECKS      DEPOSITS          LEDGER
12.32
 PROGRAM FLOWCHART
 SYMBOLS:
        BEGIN OR     INPUT OR
          END         OUTPUT

        DIRECTION

                    SUBROUTINE


        PROCESS

                     MANUAL
                    OPERATION


        DECISION
                    CONNECTOR
12.33
 PROCESS A         PROGRAM FLOWCHART:
             SEQUENCE

PROCESS B




               R

                   TRUE                PROCESS E


                                            TRUE
   PROCESS D       PROCESS C
                                   S




        SELECTION              ITERATION
12.34
 PROGRAM FLOWCHART:
         START
                                              1
                           2
           READ
                                             PRINT
                >$10,000                   REPORT

                           PROCESS A

<$10,000

     PROCESS B
                                       2   MORE?




            1                                END
 12.35
  OBJECT - ORIENTED SOFTWARE
         DEVELOPMENT
 • DE-EMPHASIZES PROCEDURES
 • SHIFTS FOCUS FROM MODELS & DATA
 • TO OBJECTS, WHICH COMBINE DATA &
   PROCEDURES
 • OBJECTS REUSABLE
 • SYSTEM: Classes; objects; relationships
   REDUCES DEVELOPMENT TIME & COST
                     *
12.36
        COMPUTER AIDED SOFTWARE
           ENGINEERING (CASE)
 • AUTOMATION OF SOFTWARE
   METHODOLOGIES
 • PRODUCES CHARTS; DIAGRAMS;
   SCREEN & REPORT GENERATORS;
     DATA DICTIONARIES; PROGRESS
   REPORTS; ANALYSIS; CHECKING
   TOOLS; CODE; DOCUMENTATION
                   *

12.37
              CASE
    COMPUTER AIDED SOFTWARE
       ENGINEERING (CASE)
  INCREASES PRODUCTIVITY & QUALITY:
  • ENFORCES DEVELOPMENT DISCIPLINE
  • IMPROVES COMMUNICATION
  • DESIGN REPOSITORY FOR OBJECTS
  • AUTOMATES TEDIOUS TASKS
  • AUTOMATES TESTING & CONTROL
  • REQUIRES ORGANIZATIONAL
     DISCIPLINE
12.38
             CASE  *
  SOFTWARE REENGINEERING


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



 • REVISE DESIGN & PROGRAM
   SPECIFICATIONS
 • FORWARD ENGINEERING: USE REVISED
   MATERIALS TO GENERATE NEW,
   STRUCTURED CODE; STRUCTURED &
   MAINTAINABLE SYSTEM
                    *
12.40
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        PRESS LEFT MOUSE BUTTON ON ICON TO
         CONNECT TO THE LAUDON & LAUDON
         WEB SITE FOR MORE INFORMATION ON
                   THIS CHAPTER


12.41
                  DIAGRAM:
        DATA FLOW DIAGRAM:

                              GENERATE
                               BALANCE
        GENERATE
          BILL

                   CUSTOMER              PAYMENT
                   FILE                  FILE

                              GENERATE
                               REPORT

        CUSTOMER



                                               MANAGER




12.42

				
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