Chapter 12
Systems Development
The Strategic
Management of
Information
Technology
Transaction Processing
System
Input Output Process
Information
Communication
Systems Development
Systems Development Life
Cycle Consists Of Six Phases
? Systems Planning
? Systems Analysis
? General Systems Design
? Systems Evaluation and Selection
? Detailed Systems Design
? Systems Implementation
3 Categories of Systems
Design
? Global-Based Systems
? Group-Based Systems
? Local-Based Systems
Global-Based Systems
? Large,Complex Information Systems that Process High
Transaction Volumes
? Complete Overhaul or Replacement of Systems Design
Components
– Old output is changed from monthly tabular reports to online
screen displays
– New processes are developed
– Input captured by scanning devices
– Old hierarchical database is converted to new relational
database with standard query language
– Controls are installed
– New technology platform composed of enterprise-wide
network topology supports systems design components
Group-Based Systems
? Serve a Single Department or other specific group of users
– smaller than,connected to global-based system
Local-Based Systems
? Concentration on Local Environment
Rapid Application Development
? Joint Application Development (JAD)
? Specialists with Advanced Tools (SWAT)
? Computer-Aided Systems and Software
Engineering (CASE Tools)
? Prototyping
Design Approaches
? Process-Oriented Approach
? Data-Oriented Approach
? Object-Oriented Approach
Design Principles
? Modularity
– Maintainability
– Reusability
? Libraries of object class catalogs
– Reliability
– Extendibility
– Standardized
– Independence
– Variety in Use
– Top-Down Design
? Start with Abstract Description of New System
? Refine View in Successive Steps
– Bottom-Up Design
? Start with Objects and Assemble them to completed
product
Process-Oriented Approach
? Based upon Stable Set of Input,Process,
and Output
? Transactions-Based Applications
– Accounts Payable
– Accounts Receivable
– Payroll
– Inventory Control
Data-Oriented Approach
? Undefined Systems Processes
? Define All Needed Data Attributes
? Systems Analysts must determine,with
users,how the system will be used
Data-Oriented Approach,
Steps
? Discuss potential decisions that will be
made from system with users of system
– Model the purchasing decision support
system through use of flexible modeling
tool
? Product Quality
? Past Performance
? Product Availability
– Divide Each Criterion into Attributes
– Develop Data Dictionary
? Size,Type,Description,Limits and Exceptions,Ranges,Security
Level,Access Privileges
? Changes,Description,Order
Object-Oriented Approach
? Catalog objects
– Found by keywords
– In a Library or Database
? Objects
– Exhibit certain behaviors
– Attributes and operations are encapsulated or
pulled together
– Operations describes how attributes are
processed
– Behave in certain ways in response to
messages
Object-Oriented Approach
? Classes
– Set of Objects that share common structure
and behavior
? Inheritance
– Objects receive attributes and operations from
other objects
– Add more attributes and operations of their
own
? Polymorphism
– Ability of object to respond to and implement
each object
Object-Oriented Steps
? Identify Object Class
? Identify Relationships
? Identify Attributes
? Determine Inheritance Relationships
? Build Class Hierarchy
– Order
– Transaction Process
– Tools Inventory
Joint Application Development
? Conceptual Systems Design Model
– Data Flow Diagram
– Entity Relationship Diagram
– Decision Table
– Screen Prototype
– Decision Tree
SDLC Strengths
? Provide Control over Development Process
? Formality
SDLC Weaknesses
? Increased Cost of Development
? Lengthened Development Time
? Difficult when Project is Hard to Define
End-User Development
? Users Develop the Prototypes
? Fourth-Generation Languages
? CASE Tools
Steps Toward Integration
? Windowing Operating System
– OS/2 Presentation Manager
– Windows
– X-Windows (Sun)
? Transaction Processing Systems
– Payroll Services
– Sales Order Processing Systems
– Process Control Systems
– Corporate Accounting Systems
Steps Toward Integration
? Multi-Tasking
– Allow Users to run different programs at the
same time
– Windows
– OS/2 (Presentation Manager)
– XWindows
? Networks
– Enable Dynamic Integration from Several
Sources
Integration
? Vertical
– Different Levels of Production
– ex,Oil Company
? Horizontal
– Retail Stores
– ex:Wal-Mart
Object-Orientation
? Different than Transmitting Raw Bits of Data
– Hardware Connections
– Access Controls
– Simple Data Formats
? Software Agents
– object-oriented programs written to perform specific tasks in
response to user requests
– agents know how to exchange object attributes
– agents have the ability to activate object functions in other
agents
? Multimedia
– Integration of Text,Video,Sound,Pictures,Animation
Integration/Links
? Static
– Hard-Coded
– Import
? Dynamic
– Linked
– Dynamic Data Exchange (DDE)
– Hot-Linked
– Object-Linking and Embedding (OLE)
? Original Software Package Automatically started
when chosen
Systems Project Proposals
? Feasibility Factors
– Technical
– Economic
– Legal
– Operational
– Schedule
? Strategic Factors
– Productivity
– Differentiation
– Management
Systems Plan
? Business Plan
– Document Company’s Goals and Objectives
– Align Systems Project with Company’s Business
Plan
? Enterprise-Wide Model
– Entity Relationship Diagram showing relationship
between organization’s entities and their
relationship to supporting strategies of Business
Plan
– View of Future Organization of Enterprise under a
Business Plan
Two Levels of Planning
? Systems Planning
– Gives Managers,Users,and Information
Systems Personnel Projects
– Establishes what should be done
– Sets a budget for the total cost of these projects
? Systems Project Planning
– Setting a plan for the development of each
specific systems project
Systems Professional Skills
? Systems Planning
– Form project team after proposed systems project is
cleared for development
? Systems Analysis
– Business Systems Analysts knowledgeable in business
? General Systems Design
– Business Systems Analysts
? Systems Evaluation and Selection
– Business Systems Analysts
? Detailed Systems Design
– Wide Range of Systems and Technical Designers
? Systems Implementation
– Systems analysts,programmers,and special
technicians
Effective Leadership Style
? Autocratic Style
– Crisis-Style Management
– Used to Correct Major Problem,such as Schedule
Slippage
? Democratic Style
– Team-oriented Leadership
– Gives each team member the freedom to achieve
goals which he/she helped set
? Laissez-Faire Style
– Highly-motivated,Highly-Skilled Team Members
– People who work best alone
Project Management Skills
? Planning
– States what should be done
– Estimates how long it will take
– Estimates what it will cost
? Leading
– Adapts to dynamics of enterprise and deals with setbacks
– Guides and induces people to perform at maximum
abilities
? Controlling
– Monitors Progress Reports and Documented Deliverables
– Compares Plans with Actuals
? Organizing
– Staffs a Systems Project Team
– Brings together users,managers,and team members
CASE
? Computer-Aided Systems and Software Engineering
? Increase Productivity of Systems Professionals
? Improve the Quality of Systems Produced
? Improve Software Maintenance Issue
? Includes,
– workstations
– central repository
– numerous modeling tools
– project management
– Systems Development Life Cycle Support
– Prototyping Applications
– Software Design Features
Central Repository
? Models Derived from Modeling Tools
? Project Management Elements
? Documented Deliverables
? Screen Prototypes and Report Designs
? Software Code from Automatic Code Generator
? Module and Object Libraries of Reusable Code
? Reverse Engineering,Reengineering,and
Restructuring Features
Software Maintenance
? Reverse Engineering
– Extract original design from spaghetti-like,undocumented
code to make maintenance change request
– Abstract meaningful design specifications that can be used
by maintenance programmers to perform maintenance tasks
? Reengineering
– Examination and changing of a system to reconstitute it in
form and functionality
– Reimplementation
? Restructuring
– Restructures code into standard control constructs
? sequence,selection,repetition
Work Group Technologies
? Suite of Products
? GroupWare
Examples of Suite of Products
? Microsoft Corporation
– Word
– Excel
– PowerPoint
? Lotus Development Corporation
– AmiPro
– Lotus 1-2-3
– Freelance
? Novell/Borland
– WordPerfect
– Borland
– dBaseIV
Advantages of Suite of Products
? Integrated Document
? Economies of Scale
? Consolidated Training
? Shared Files Across Group
Disadvantages of Suite of Products
? Choice Based upon Group Rather than
Advantages of Individual Product
?,Locked In” to Product Company
? Difficulty in Matching Client Requirements
Today’s Organization
? Enterprise-Wide Development
? Object-Oriented Definition
? Implementation of Suite Approach
Unsuccessful Systems
? Systems were developed which did not support business strategies and
objectives,
? Poor systems planning and inadequate project management,
? Failure to define or understand user requirements,
? Negligence in estimating costs and benefits of the systems project,
? Creation of a myriad of design defects and errors,
? Acquisition of computers and software that no one needs or knows
how to use,
? Installation of incompatible or inadequate technology,
? Negligence in implementing adequate controls,
? Development of unstructured,unmaintainable software,
? Inadequate implementation tasks,
PDM
?Productivity
?Differentiation
?Management
Project Management
? Gantt Chart
? Pert Chart
Gantt Chart
? Compares Planned Performance against
actual performance to determine whether
the project is ahead of,behind,or on
schedule
? Schedule a complete systems project by
phases
PERT Chart
? Estimate,Schedule,and Control a network of interdependent
tasks
? Shown by arrows,nodes,or circles
? Program,Evaluation and Renew Technique
? Determine minimum time needed to complete a project,phase,
or task
? Critical Path
– Minimum time needed to complete a project or phase
– Total of the most time-consuming chain of events
? Four Steps
– Identify Tasks
– Determine Proper Sequence of Tasks
– Estimate the Time Required to Perform each Task
– Prepare Time-Scaled Chart of Tasks and Events to
Determine the Critical Path
Systems Development
The Strategic
Management of
Information
Technology
Transaction Processing
System
Input Output Process
Information
Communication
Systems Development
Systems Development Life
Cycle Consists Of Six Phases
? Systems Planning
? Systems Analysis
? General Systems Design
? Systems Evaluation and Selection
? Detailed Systems Design
? Systems Implementation
3 Categories of Systems
Design
? Global-Based Systems
? Group-Based Systems
? Local-Based Systems
Global-Based Systems
? Large,Complex Information Systems that Process High
Transaction Volumes
? Complete Overhaul or Replacement of Systems Design
Components
– Old output is changed from monthly tabular reports to online
screen displays
– New processes are developed
– Input captured by scanning devices
– Old hierarchical database is converted to new relational
database with standard query language
– Controls are installed
– New technology platform composed of enterprise-wide
network topology supports systems design components
Group-Based Systems
? Serve a Single Department or other specific group of users
– smaller than,connected to global-based system
Local-Based Systems
? Concentration on Local Environment
Rapid Application Development
? Joint Application Development (JAD)
? Specialists with Advanced Tools (SWAT)
? Computer-Aided Systems and Software
Engineering (CASE Tools)
? Prototyping
Design Approaches
? Process-Oriented Approach
? Data-Oriented Approach
? Object-Oriented Approach
Design Principles
? Modularity
– Maintainability
– Reusability
? Libraries of object class catalogs
– Reliability
– Extendibility
– Standardized
– Independence
– Variety in Use
– Top-Down Design
? Start with Abstract Description of New System
? Refine View in Successive Steps
– Bottom-Up Design
? Start with Objects and Assemble them to completed
product
Process-Oriented Approach
? Based upon Stable Set of Input,Process,
and Output
? Transactions-Based Applications
– Accounts Payable
– Accounts Receivable
– Payroll
– Inventory Control
Data-Oriented Approach
? Undefined Systems Processes
? Define All Needed Data Attributes
? Systems Analysts must determine,with
users,how the system will be used
Data-Oriented Approach,
Steps
? Discuss potential decisions that will be
made from system with users of system
– Model the purchasing decision support
system through use of flexible modeling
tool
? Product Quality
? Past Performance
? Product Availability
– Divide Each Criterion into Attributes
– Develop Data Dictionary
? Size,Type,Description,Limits and Exceptions,Ranges,Security
Level,Access Privileges
? Changes,Description,Order
Object-Oriented Approach
? Catalog objects
– Found by keywords
– In a Library or Database
? Objects
– Exhibit certain behaviors
– Attributes and operations are encapsulated or
pulled together
– Operations describes how attributes are
processed
– Behave in certain ways in response to
messages
Object-Oriented Approach
? Classes
– Set of Objects that share common structure
and behavior
? Inheritance
– Objects receive attributes and operations from
other objects
– Add more attributes and operations of their
own
? Polymorphism
– Ability of object to respond to and implement
each object
Object-Oriented Steps
? Identify Object Class
? Identify Relationships
? Identify Attributes
? Determine Inheritance Relationships
? Build Class Hierarchy
– Order
– Transaction Process
– Tools Inventory
Joint Application Development
? Conceptual Systems Design Model
– Data Flow Diagram
– Entity Relationship Diagram
– Decision Table
– Screen Prototype
– Decision Tree
SDLC Strengths
? Provide Control over Development Process
? Formality
SDLC Weaknesses
? Increased Cost of Development
? Lengthened Development Time
? Difficult when Project is Hard to Define
End-User Development
? Users Develop the Prototypes
? Fourth-Generation Languages
? CASE Tools
Steps Toward Integration
? Windowing Operating System
– OS/2 Presentation Manager
– Windows
– X-Windows (Sun)
? Transaction Processing Systems
– Payroll Services
– Sales Order Processing Systems
– Process Control Systems
– Corporate Accounting Systems
Steps Toward Integration
? Multi-Tasking
– Allow Users to run different programs at the
same time
– Windows
– OS/2 (Presentation Manager)
– XWindows
? Networks
– Enable Dynamic Integration from Several
Sources
Integration
? Vertical
– Different Levels of Production
– ex,Oil Company
? Horizontal
– Retail Stores
– ex:Wal-Mart
Object-Orientation
? Different than Transmitting Raw Bits of Data
– Hardware Connections
– Access Controls
– Simple Data Formats
? Software Agents
– object-oriented programs written to perform specific tasks in
response to user requests
– agents know how to exchange object attributes
– agents have the ability to activate object functions in other
agents
? Multimedia
– Integration of Text,Video,Sound,Pictures,Animation
Integration/Links
? Static
– Hard-Coded
– Import
? Dynamic
– Linked
– Dynamic Data Exchange (DDE)
– Hot-Linked
– Object-Linking and Embedding (OLE)
? Original Software Package Automatically started
when chosen
Systems Project Proposals
? Feasibility Factors
– Technical
– Economic
– Legal
– Operational
– Schedule
? Strategic Factors
– Productivity
– Differentiation
– Management
Systems Plan
? Business Plan
– Document Company’s Goals and Objectives
– Align Systems Project with Company’s Business
Plan
? Enterprise-Wide Model
– Entity Relationship Diagram showing relationship
between organization’s entities and their
relationship to supporting strategies of Business
Plan
– View of Future Organization of Enterprise under a
Business Plan
Two Levels of Planning
? Systems Planning
– Gives Managers,Users,and Information
Systems Personnel Projects
– Establishes what should be done
– Sets a budget for the total cost of these projects
? Systems Project Planning
– Setting a plan for the development of each
specific systems project
Systems Professional Skills
? Systems Planning
– Form project team after proposed systems project is
cleared for development
? Systems Analysis
– Business Systems Analysts knowledgeable in business
? General Systems Design
– Business Systems Analysts
? Systems Evaluation and Selection
– Business Systems Analysts
? Detailed Systems Design
– Wide Range of Systems and Technical Designers
? Systems Implementation
– Systems analysts,programmers,and special
technicians
Effective Leadership Style
? Autocratic Style
– Crisis-Style Management
– Used to Correct Major Problem,such as Schedule
Slippage
? Democratic Style
– Team-oriented Leadership
– Gives each team member the freedom to achieve
goals which he/she helped set
? Laissez-Faire Style
– Highly-motivated,Highly-Skilled Team Members
– People who work best alone
Project Management Skills
? Planning
– States what should be done
– Estimates how long it will take
– Estimates what it will cost
? Leading
– Adapts to dynamics of enterprise and deals with setbacks
– Guides and induces people to perform at maximum
abilities
? Controlling
– Monitors Progress Reports and Documented Deliverables
– Compares Plans with Actuals
? Organizing
– Staffs a Systems Project Team
– Brings together users,managers,and team members
CASE
? Computer-Aided Systems and Software Engineering
? Increase Productivity of Systems Professionals
? Improve the Quality of Systems Produced
? Improve Software Maintenance Issue
? Includes,
– workstations
– central repository
– numerous modeling tools
– project management
– Systems Development Life Cycle Support
– Prototyping Applications
– Software Design Features
Central Repository
? Models Derived from Modeling Tools
? Project Management Elements
? Documented Deliverables
? Screen Prototypes and Report Designs
? Software Code from Automatic Code Generator
? Module and Object Libraries of Reusable Code
? Reverse Engineering,Reengineering,and
Restructuring Features
Software Maintenance
? Reverse Engineering
– Extract original design from spaghetti-like,undocumented
code to make maintenance change request
– Abstract meaningful design specifications that can be used
by maintenance programmers to perform maintenance tasks
? Reengineering
– Examination and changing of a system to reconstitute it in
form and functionality
– Reimplementation
? Restructuring
– Restructures code into standard control constructs
? sequence,selection,repetition
Work Group Technologies
? Suite of Products
? GroupWare
Examples of Suite of Products
? Microsoft Corporation
– Word
– Excel
– PowerPoint
? Lotus Development Corporation
– AmiPro
– Lotus 1-2-3
– Freelance
? Novell/Borland
– WordPerfect
– Borland
– dBaseIV
Advantages of Suite of Products
? Integrated Document
? Economies of Scale
? Consolidated Training
? Shared Files Across Group
Disadvantages of Suite of Products
? Choice Based upon Group Rather than
Advantages of Individual Product
?,Locked In” to Product Company
? Difficulty in Matching Client Requirements
Today’s Organization
? Enterprise-Wide Development
? Object-Oriented Definition
? Implementation of Suite Approach
Unsuccessful Systems
? Systems were developed which did not support business strategies and
objectives,
? Poor systems planning and inadequate project management,
? Failure to define or understand user requirements,
? Negligence in estimating costs and benefits of the systems project,
? Creation of a myriad of design defects and errors,
? Acquisition of computers and software that no one needs or knows
how to use,
? Installation of incompatible or inadequate technology,
? Negligence in implementing adequate controls,
? Development of unstructured,unmaintainable software,
? Inadequate implementation tasks,
PDM
?Productivity
?Differentiation
?Management
Project Management
? Gantt Chart
? Pert Chart
Gantt Chart
? Compares Planned Performance against
actual performance to determine whether
the project is ahead of,behind,or on
schedule
? Schedule a complete systems project by
phases
PERT Chart
? Estimate,Schedule,and Control a network of interdependent
tasks
? Shown by arrows,nodes,or circles
? Program,Evaluation and Renew Technique
? Determine minimum time needed to complete a project,phase,
or task
? Critical Path
– Minimum time needed to complete a project or phase
– Total of the most time-consuming chain of events
? Four Steps
– Identify Tasks
– Determine Proper Sequence of Tasks
– Estimate the Time Required to Perform each Task
– Prepare Time-Scaled Chart of Tasks and Events to
Determine the Critical Path
