Systems Development Life Cycle SDLC

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Systems Development Life Cycle (SDLC)

• Often called Waterfall Model
• Iterative Process
• Control cost and time
• Budgets
• Project timelines and deadlines
• Works best with well understood systems
• Employed on most large development projects.

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Systems Development Life Cycle (SDLC)
Project ID and Selection
Proj. Initiation Planning
Analysis
Logical Design
Physical Design
Implementation
Maintenance
Hoffer, George Valacich
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Revised CASE PhasesKoletzke and Dorsey
Strategy
Analysis
Design
Build
Test
Implementation
Maintenance
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SDLC Phases

• Systems Investigation
• Project ID and Selection
• Project Initiation and Planning
• Systems Analysis
• Analysis
• Systems Design
• Logical Design
• Physical Design
• Systems Implementation
• Implementation
• Systems Maintenance and Review
• Maintenance

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Systems Investigation
Network or
Data Processes Technology
Lists of entities important to the business
Overview of technology architecture.
Lists of functions that the business
performs. (BPM)
Ballpark (Business Scope)
Enterprise communication diagram
Functional Hierarchy Diagram
Owner (Business Model)
E-R Diagrams (Entity Level)
E-R Diagrams (Attribute Level)
Distribution Diagram
Designer (IS Model)
Dataflow Diagrams
Database Design
Configuration Design
Process Specifications
Builder (Technology Model)
Schema and Sub-schema Definition
Detailed (Technology Specification)
Configuration Definition
Program Code
Working Application
Installed Infrastructure
Functional System
Physical Tables
6
Systems Investigation

• Alignment with Strategic Goals
• Statements of goals, critical success factors,
• organizational relationships.
• High level modeling of enterprise data,
• processes and infrastructure.
• Project ID and Selection Selection
• Project Proposals
• Project prioritization
• Feasibility Studies
• Project Initiation and Planning
• Staffing, Budget, Delivery Dates

7
Analysis
Network or
Data Processes Technology
Lists of entities important to the business
Overview of technology architecture.
Lists of functions that the business
performs. (BPM)
Ballpark (Business Scope)
Enterprise communication diagram
Functional Hierarchy Diagram
Owner (Business Model)
E-R Diagrams (Entity Level)
E-R Diagrams (Attribute Level)
Distribution Diagram
Designer (IS Model)
Dataflow Diagrams
Database Design
Configuration Design
Process Specifications
Builder (Technology Model)
Schema and Sub-schema Definition
Detailed (Technology Specification)
Configuration Definition
Program Code
Working Application
Installed Infrastructure
Functional System
Physical Tables
8
Systems Analysis

• Data Collection
• Strengths/Weaknesses of existing system - What
  features of the existing system should be kept?
  Can the existing system be modified to meet
  goals?
• Data Analysis
• Identification of important entities - What
  people, events, organizations, things, concepts
  etc. are important to the business model?
• Requirements Analysis
• Identifying needs - What functions must the
  system be able to provide? What functions would
  be nice to have?

9
Design
Network or
Data Processes Technology
Lists of entities important to the business
Overview of technology architecture.
Lists of functions that the business
performs. (BPM)
Ballpark (Business Scope)
Enterprise communication diagram
Functional Hierarchy Diagram
Owner (Business Model)
E-R Diagrams (Entity Level)
E-R Diagrams (Attribute Level)
Distribution Diagram
Designer (IS Model)
Dataflow Diagrams
Database Design
Configuration Design
Process Specifications
Builder (Technology Model)
Schema and Sub-schema Definition
Detailed (Technology Specification)
Configuration Definition
Program Code
Working Application
Installed Infrastructure
Functional System
Physical Tables
10
Systems Design

• Logical Design
• Functional requirements of the system -
  Specification of the data, processes and
  communication requirements without regard to how
  they will be implemented.
• Physical Design
• Specifies system components - The application of
  technology solutions to the logical design
  specifications
• Design Alternatives
• Examine other methods to meet design
  specifications.
• Evaluating and Selecting a Design
• Select the alternative that meets the
  specifications at the lowest overall cost.

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Implementation and Maintenance
Network or
Data Processes Technology
Lists of entities important to the business
Overview of technology architecture.
Lists of functions that the business
performs. (BPM)
Ballpark (Business Scope)
Enterprise communication diagram
Functional Hierarchy Diagram
Owner (Business Model)
E-R Diagrams (Entity Level)
E-R Diagrams (Attribute Level)
Distribution Diagram
Designer (IS Model)
Dataflow Diagrams
Database Design
Configuration Design
Process Specifications
Builder (Technology Model)
Schema and Sub-schema Definition
Detailed (Technology Specification)
Configuration Definition
Program Code
Working Application
Installed Infrastructure
Functional System
Physical Tables
12
Systems Implementation

• Coding
• Hardware/Software Acquisition
• User Preparation
• Hiring and Training Personnel
• Site Preparation
• Data Preparation
• Installation
• Testing
• Startup
• User Acceptance

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Systems Maintenance

• Types
• Patch
• New Release
• New Version
• 5 times the cost of development
• 50 - 70 of programmers time
• Documentation is important!

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SDLC Criticisms

• Process Overhead
• Significant time and resource costs.
• Project Milestones
• Discourages iterative changes to higher level
  models in
• light of lower level developments.
• Not suited for poorly understood systems.
• Difficult to apply if system requirements are
  not well
• defined.
• Testing Methodology
• Bottom up testing may result in components that
  work
• separately but not together.