Database Management Systems MIS 372

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Database Management Systems MIS 372

• WSU Vancouver
• Shaun Simpson
• Fall 1998

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Chapter 4
THE PROCESS OF DATABASE PLANNING AND DEVELOPMENT
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Information Systems Development

• 3 Dimensions of Information Systems - Zachman
• What Data
• Where Network Elements
• How Processes

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Outline

• A Design Framework for Information System
  Architecture (ISA)
• A Design Methodology for IS/DB - Information
  Engineering
• An Example - Pine Valley Furniture

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Zachmans Framework for Information System
Architecture

• Information System Architecture
• A conceptual blue print/plan that addresses the
  desired structure of an information system for
  an organization
• Zachmans framework
• Present a 3-component (Data, Process, and
  Network) 6-stage analytical framework for ISA
  development
• A template for IS development

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Zachmans Framework
Q. What is the focus of each component at each
stage?
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Zachmans Framework
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Zachmans Framework
DATA
PROCESS
NETWORK
Business Scope
1
How should it be obtained?
Enterprise Model
2
What should we store or provide?
Information Sys. Model
3
Technology Model
4
Technology Definition
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Information System
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Zachmans Framework
DATA
PROCESS
NETWORK
Business Scope
1
How should it be obtained?
Where should it be stored?
Enterprise Model
2
What should we store or provide?
Information Sys. Model
3
Technology Model
4
Technology Definition
5
Information System
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Zachmans Framework
DATA
PROCESS
NETWORK
Business Scope
1

• A top-down approach
• Involves a trans-formation between every two
  stages (not a modification!)
• Good for enterprise data modeling
• Serve as a template

Enterprise Model
2
Information Sys. Model
3
Technology Model
4
Technology Definition
5
Information System
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A Methodology Information Engineering

• A Methodology
• A formal process (steps) that can be followed to
  achieve design goals and details
• Information Engineering
• an enterprise-wide, data-driven methodology to
  develop an Information System Architecture!!

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Information Engineering
Planning
Analysis
Design
Implementation
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Information Engineering

• Identify business strategies
• Goals, functions, entities
• High-level enterprise model
• Data Requirement Analysis
• Detailed conceptual model
• Data Normalization
• Map to specific technology
• Database definitions
• Applications development

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Information Engineering
Planning
High-level E-R Diagram
Analysis
Detailed E-R Diagram
Design
Normalized DB Model
Implement- ation
Databases
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A Contrast Between Zachmans Framework and IE
Methodology
Zachmans Framework
Inf. Eng. Method.
Business Scope
High-Level E-R Diagram
1
Planning
2
Enterprise Model
Information Sys. Model
Analysis
3
Detailed E-R Diagram
Normalized Design Specific DB Technology
Technology Model
Design
4
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Technology Definition
DB Definition App. Coding Physical Database
Implement- ation
Information System
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Information Engineering on Pine Valley
Furniture 1. Planning - Brainstorming

• 1. Strategic Planning -

1. Goals maintain 15 ROI 2. Critical
Success Factors (CSF) On-time
deliveries 3. Problems Areas ... Inaccurate
forecasts Stockouts
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Information Engineering on Pine Valley
Furniture 1. Planning ? Model Results

• An Enterprise Model (High-Level)

CUTOMER
ORDER
INVOICE
PRODUCT
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Information Engineering on Pine Valley
Furniture 2. Analysis ? Process Model

• Through functional/process analysis, it leads to

A Data Flow Diagram (DFD)
Process Order Request
Order
Create Order
Order File
D1
New Customer
Reject order
Validate
Check Customer Credit
Create New Customer
Create New Account
Customer File
D2
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Information Engineering on Pine Valley
Furniture 2. Analysis - Detailed E-R Model
A Refined E-R Diagram
...
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Information Engineering on Pine Valley
Furniture 3. Design - A Normalized DB
A Set of Normalized Database Tables
CUSTOMER
PRODUCT
INVOICE
ORDER
...
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Information Engineering on Pine Valley Furniture
4. Implementation - Coding and Testing

• It covers the following
• Selection of Software/Hardware
• DB Definitions
• Application Coding
• Testing
• Installation and tuning

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Database Design and Development A Summary
Chapter 4
Chapter 3 5
Chapter 2 4
Chapter 6
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Methodologies for Information Systems Development

• The Systems Development Life Cycle Methodology
  (SDLC)
• Investigation, Analysis, Design, Implementation,
  Maintenance
• The Information Engineering Development Cycle
  (IE)
• Planning, Analysis, Design, Implementation
• Tool based with system encyclopedia
• The Prototyping Development Cycle

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The Systems Development Life Cycle
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Systems Development Life Cycle

• Traditional
• Step by Step
• Single Project Focus
• Process Centered
• Data-Flow Diagram

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Systems Development Life Cycle

• Advantages
• Large Systems
• Highly Structured
• Complex
• Disadvantages
• Costly
• Time-Consuming
• Inflexible

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The Information Engineering Development Model
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The Information Engineering Development Model

• Organizational Approach
• Data Focus
• Informational Model
• CASE tools
• Advantages More closely tied to organization and
  data
• Disadvantages CASE tools do not always produce
  optimized systems, Tools still being refined, Can
  be costly to train and use

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The Prototyping Development Cycle
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Prototyping Development Cycle

• Rapid Iterative Processes
• Requirements
• Design
• Implementation
• Advantages Good for poorly understood problem,
  interactive, flexible, focus on users
• Disadvantages Does not scale well, Hard to keep
  iterative process going

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Data Planning

• Information as a Resource - Strategic Advantage
• The Data Planning Process
• CASE Tools for Data Planning
• Business Process Re-engineering
• Data Planning and Data Warehousing

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Database Development and Systems Development
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Affinity Matrix Entities Vs. Functions for Apex
Products
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Database Development

• A model of Database Development in a Systems
  Development Context
• Systems Analysis
• Conceptual Database Design
• Physical Database Design and Implementation
• Application System Analysis, Design and
  Implementation

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A Database-Oriented Systems Development Model
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A Sample Layout Form
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Simple E-R Diagram
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Three Schemas Architecture
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CASE Tools and the Development Process

• CASE and I-CASE
• The CASE Tool as a Systems Repository

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Terms and Definitions

• Information Systems Architecture - An overall
  plan for the structure of information systems in
  an organization described in terms of data,
  process and network elements.
• Systems Development Life Cycle (SDLC) - A
  methodology for the development of information
  systems that divides the process into the five
  stages of investigation, analysis, design,
  implementation, and maintenance.
• Computer Assisted Software Engineering (CASE)
  tools - software products designed to support one
  or more phases of the planning and/or development
  of information systems.

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Terms Continued

• Information Engineering (IE) - An information
  systems development methodology whose phases are
  planning, analysis, design, and implementation.
  The IE methodology calls for computer generation
  of applications based on conceptual level
  specifications. It requires the use of I-CASE
  tools.
• Integrated CASE (I-CASE) products - products that
  provide an integrated set of tools supporting all
  stages of the planning and development of
  information systems from data and IS planning
  through automated generation of programs to
  implement applications.
• Prototyping Development Cycle - An information
  systems development methodology where systems are
  developed through rapid, iterative, processes of
  gathering requirements, designing and
  implementing a prototype for user feedback.

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Terms Continued

• Information Resource Management - Information
  resource management is a concept that views
  information as a resource that can be used to
  strategic advantage. To achieve this the
  information resource must be effectively planned
  and must be readily accessible to users
  throughout the organization.
• Data Planning - A process used to identify
  information needed to support strategic plans of
  the organization. Data planning identifies basic
  entities that need to be represented in databases
  and helps to define the scope of business area or
  subject area databases to be developed.
• Subject Area Database - A database containing
  data that is needed to support a set of related
  processes within an organization. The set of data
  within a subject area database should be highly
  interrelated but as independent as possible of
  data in other subject area databases.

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Terms Continued

• Business Process Reengineering - A methodology or
  approach to data planning and IS development that
  requires the reorganization and streamlining of
  business processes as a part of the
  implementation of the information system.
• Data Warehouse - A database or set of databases
  distinct from operational databases that contains
  historical, summarized data from broad sectors of
  the organization needed to support decision
  making.
• Database Development - The analysis, design, and
  implementation of a database system.
• Three Schema Architecture - An architecture for
  databases developed by ANSI/SPARC that identifies
  three levels of models external models, the
  conceptual model, and the internal model. It is
  designed to insulate users and applications from
  changes in the internal and conceptual models.

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Terms Continued...

• External Model - The model of a database from the
  perspective of an individual user or group of
  users, a user view.
• Internal Model - The model that describes how
  data are physically stored in a database system.
• Hyper-diagrams - Sets of interconnected diagrams
  produced by a CASE or I-CASE tool. Hyper-diagrams
  allow a virtually unlimited number of objects to
  be interconnected, thus, supporting the complex
  interrelationships among design components.
• Systems Repository - A collection containing all
  forms of information required to develop
  information system including planning
  information, business rules, and data and
  processing requirements.