Title: 12. ALTERNATIVE SYSTEM-BUILDING METHODS
112. ALTERNATIVE SYSTEM-BUILDING METHODS
12.1
2DETERMINING SYSTEM DEVELOPMENT STRATEGY CONTROLLIN
G DEVELOPMENT OUTSIDE INFO SYSTEM DEPARTMENT FITS
FIRMS INFO ARCHITECTURE STRATEGIC PLAN
12.2
3SYSTEM 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
12.3
4SYSTEM 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
12.4
5SYSTEM LIFECYCLE
- CAN BE COSTLY, TIME CONSUMING
- MAY ENCOURAGE FREEZING SPECIFICATIONS EARLY IN
DEVELOPMENT - MAY NOT BE SUITABLE FOR SMALL, LESS STRUCTURED
SYSTEMS
12.5
6PROTOTYPING
- 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
12.6
7STEPS IN PROTOTYPING
- IDENTIFY USERS REQUIREMENTS
- DEVELOP PROTOTYPE
- USE PROTOTYPE
- REVISE ENHANCE PROTOTYPE
- BEST FOR DESIGN OF END-USER INTERFACE How
End-user Interacts With System
12.7
8APPLICATION SOFTWARE PACKAGES
- REWRITTEN, PRECODED APPLICATION SOFTWARE,
COMMERCIALLY AVAILABLE FOR SALE OR LEASE - GEARED TO COMMON REQUIREMENTS
- CUSTOMIZATION Modification of Software to Meet
Organizations Needs - MUST WEIGH COSTS / BENEFITS
12.8
9SELECTED EXAMPLES OF APPLICATION PROGRAMS
- ACCOUNTS PAYABLE/RECEIVABLE ARCHITECTURAL
DESIGN BANKING CHECK PROCESSING
COMPUTER-AIDED-DESIGN DOCUMENT IMAGING
ENGINEERING E-MAIL FINANCIAL CONTROL
FORECASTING FORMS DESIGN GRAPHICS HOTEL
MANAGEMENT HUMAN RESOURCES INSTALLMENT LOANS
INVENTORY CONTROL JOB COSTING/SCHEDULING LIFE
INSURANCE MAILING LABELS MATHEMATICAL /
STATISTICAL MODELING ORDER ENTRY PAYROLL
PROCESS CONTROL REAL ESTATE MANAGEMENT SALES
DISTRIBUTION SAVINGS SYSTEMS STOCK MANAGEMENT
TAX ACCOUNTING UTILITY CONTROLS WORD PROCESSING
12.9
10USE APPLICATION PACKAGES
- 1. Where Functions are Common to many Companies
- 2. Where In-House Resources are Scarce
- 3. When Microcomputer Applications are being
Developed for End Users
12.10
11CUSTOMIZATION
- MODIFYING SOFTWARE PACKAGE
- TO MEET ORGANIZATIONS UNIQUE REQUIREMENTS
- WITHOUT DESTROYING INTEGRITY
- OF PACKAGE
- RAISES DEVELOPMENT COSTS
12.11
12EFFECTS OF CUSTOMIZING SOFTWARE ON TOTAL
IMPLEMENTATION COSTS
10
8
6
TOTAL IMPLEMENTATION
COSTS
4
2
0
0.5
1
2
3
4
5
LINES OF CODE CONVERTED
12.12
13REQUEST FOR PROPOSAL (RFP)
- Detailed list of Questions
- Submitted to Vendors
- to Determine if Vendors Product meets
Organizations Specific Requirements
12.13
14PACKAGE EVALUATION CRITERIA
- FUNCTIONS INCLUDED
- FLEXIBILITY
- USER FRIENDLINESS
- HARDWARE SOFTWARE RESOURCES
- DATABASE/FILE CHARACTERISTICS
- INSTALLATION EFFORTS
- MAINTENANCE
- DOCUMENTATION
- VENDOR QUALITY
- COST
12.14
15APPLICATION PACKAGE DEVELOPMENT CYCLE
- SYSTEMS ANALYSIS
- SYSTEMS DESIGN
- PROGRAMMING, TESTING, CONVERSION
- PRODUCTION MAINTENANCE
12.15
16SYSTEMS ANALYSIS
- Identify Problem User Requirements
Alternatives Vendors - Package vs. In-House Development
- Evaluate Packages
- Select Package
12.16
17SYSTEMS DESIGN
- Tailor Package Features
- Train Technical Staff
- Prepare Physical Design
- Customize Package Design
- Organizational Procedures
12.17
18PROGRAMMING, TESTING, CONVERSION
- Install Package
- Implement Modifications
- Design Program Interfaces
- Documentation
- Convert to Package System
- Test System
- Train Users on Package
12.18
19PRODUCTION MAINTENANCE
- Correct Problems
- Install Updates, Enhancements to Package
12.19
20END-USER DEVELOPMENT
- END-USERS DEVELOP INFORMATION SYSTEM
- WITH LITTLE HELP FROM
- TECHNICAL SPECIALISTS
- USING 4th GENERATION TOOLS
12.20
21END-USER DEVELOPMENT
- STRENGTHS
- INCREASED PRODUCTIVITY USING 4th GENERATION TOOLS
- QUERY LANGUAGES
- GRAPHICS
- REPORT GENERATORS
- APPLICATION GENERATORS
- SHORT DEVELOPMENT TIMES
12.21
22END-USER DEVELOPMENT
- WEAKNESSES
- RELATIVELY INEFFICIENT
- SLOW TRANSACTION PROCESSING
- MAY CARRY HIGH COST
- LARGE FILES CAN DEGRADE PERFORMANCE
- NONPROCEDURAL APPROACH MAY HAMPER LOGIC
UPDATING REQUIREMENTS
12.22
23END-USER DEVELOPMENT
- MANAGEMENT BENEFITS
- IMPROVED REQUIREMENTS DETERMINATION
- INCREASED USER INVOLVEMENT SATISFACTION
- DEVELOPMENT CONTROLLED BY USERS
- REDUCED APPLICATION BACKLOG
12.23
24END-USER DEVELOPMENT
- MANAGEMENT PROBLEMS
- INSUFFICIENT REVIEW / ANALYSIS
- LACK OF STANDARDS CONTROLS
- UNCONTROLLED DATA
- PROLIFERATION OF PRIVATE INFO SYSTEMS
12.24
25END-USER DEVELOPMENT
- INFORMATION CENTER
- SPECIAL FACILITY WITHIN ORGANIZATION
- PROVIDES TRAINING, SUPPORT FOR
- END-USER COMPUTING
12.25
26OUTSOURCING
- CONTRACTING
- COMPUTER CENTER OPERATIONS
- TELECOMMUNICATIONS NETWORKS
- APPLICATION DEVELOPMENT
- TO EXTERNAL VENDORS
12.26
27ADVANTAGES OF OUTSOURCING
- ECONOMY
- SERVICE QUALITY
- PREDICTABILITY
- FLEXIBILITY
- MAKING FIXED COSTS VARIABLE
- FREEING UP HUMAN RESOURCES
- FREEING UP CAPITAL
12.27
28DISADVANTAGES OF OUTSOURCING
- LOSS OF CONTROL
- VULNERABILITY OF STRATEGIC INFORMATION
- DEPENDENCY
12.28
29REWARDS PENALTIES OF OUTSOURCING
HIGH
AIRLINE RESERVATIONS
PAYROLL
PLANT SCHEDULING
PENALTY FOR PROBLEMS
HIGH OUTSOURCING POTENTIAL
ENGINEERING ANALYSIS TOOLS
CAFETERIA ACCOUNTING
LOW
HIGH
REWARDS FOR EXCELLENCE
12.29
3012. ALTERNATIVE SYSTEM-BUILDING METHODS
12.30