Chap 02 Corrected

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Chapter 2

apter :

The Database

Development Process

Modern Database Management

8th Edition

Jeffrey A. Hoffer, Mary B. Prescott,

Fred R. McFadden2

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Chapter 2

Objectives

Definition of terms

Describe system development life cycle

Explain prototyping approach

Explain roles of individuals Explain three-schema approach

Explain role of packaged data models

Explain three-tiered architectures

Explain scope of database design projects

Draw simple data models

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Chapter 2

Enterprise Data Model

First step in database development

Specifies scope and general content

Overall picture of organizational data at high

level of abstraction

Entity-relationship diagram

Descriptions of entity types

Relationships between entities

Business rules

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Chapter 2

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Figure 2-1 Segment from enterprise data model

Enterprise data model

describes the high-

level entities in an

organization and therelationship between

these entities

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Chapter 2

Information Systems Architecture

(ISA)

Conceptual blueprint for organizations desiredinformation systems structure

Consists of: Data (e.g. Enterprise Data Modelsimplified ER Diagram)

Processesdata flow diagrams, process decomposition, etc.

Data Networktopology diagram (like Fig 1-9)

Peoplepeople management using project managementtools (Gantt charts, etc.)

Events and points in time (when processes are performed)

Reasons for events and rules (e.g., decision tables)

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Chapter 2

Information Engineering

A data-oriented methodology to create andmaintain information systems

Top-down planninga generic IS planningmethodology for obtaining a broad understandingof the IS needed by the entire organization

Four steps to Top-Down planning: Planning

Analysis

Design

Implementation

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Chapter 2

Information Systems Planning

(Table 2-1)

Purposealign information technology with

organizations business strategies

Three steps:1. Identify strategic planning factors

2. Identify corporate planning objects

3.Develop enterprise model

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Chapter 2

Identify Strategic Planning Factors

(Table 2-2)

Organization goalswhat we hope to accomplish

Critical success factorswhat MUST work in order for us to

survive

Problem areasweaknesses we now have

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Chapter 2

Identify Corporate Planning

Objects (Table 2-3) Organizational unitsdepartments

Organizational locations

Business functionsgroups of business processes Entity typesthe things we are trying to model for the database

Information systemsapplication programs

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Chapter 2

Develop Enterprise Model

Functional decomposition

Iterative process breaking system description into finer and finerdetail

Enterprise data model

Planning matrixes

Describe interrelationships

between planning objects

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Chapter 2

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Figure 2-2 Example of process decomposition of anorder fulfillment function (Pine Valley Furniture)

Decomposition = breaking

large tasks into smaller tasks

in a hierarchical structure

chart

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Chapter 2

Planning Matrixes

Describe relationships between planning objects in the organization

Types of matrixes:

Function-to-data entity

Location-to-function

Unit-to-function

IS-to-data entity

Supporting function-to-data entity

IS-to-business objective

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Chapter 2

Example business function-to-data

entity matrix (Fig. 2-3)

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Chapter 2

Two Approaches to Database

and IS Development

SDLC System Development Life Cycle Detailed, well-planned development process Time-consuming, but comprehensive Long development cycle

Prototyping Rapid application development (RAD) Cursory attempt at conceptual data modeling Define database during development of initial prototype Repeat implementation and maintenance activities with new

prototype versions

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Chapter 2

Systems Development Life Cycle

(see also Figures 2.4, 2.5)

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

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Chapter 2


(see also Figures 2.4, 2.5) (cont.)

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Planning Purposepreliminary understanding

Deliverablerequest for study

Database activity

enterprise modeling and

early conceptual data

modeling

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Analysis

Purpose

thorough requirements analysis and

structuring

Deliverablefunctional system specifications

Database activity

Thoroughand integrated conceptual

data modeling

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical DesignLogical Design

Purpose

information requirements elicitationand structure

Deliverabledetailed design specifications

Database activity

logical database design

(transactions, forms,

displays, views, data

integrity and security)

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Physical Design

Purpose

develop technology and

organizational specifications

Deliverableprogram/data

structures, technology purchases,

organization redesigns

Database activity

physical database design (define

database to DBMS, physical

data organization, database

processing programs)

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Implementation

Purpose

programming, testing, training,installation, documenting

Deliverableoperational programs,

documentation, training materials

Database activity

database implementation,

including coded programs,

documentation,

installation and conversion

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Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design

Maintenance

Purposemonitor, repair, enhance

Deliverableperiodic audits

Database activity

database maintenance,

performance analysis

and tuning, error

corrections

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Chapter 2

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Prototyping Database Methodology(Figure 2.6)

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Prototyping Database Methodology


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Chapter 2

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(Figure 2.6) (cont.)

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Chapter 2

CASE

Computer-Aided Software Engineering (CASE)software tools providingautomated support for systems development

Three database features:

Data modelingdrawing entity-relationship diagrams

Code generationSQL code for table creation Repositoriesknowledge base of enterprise information

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Chapter 2

Packaged Data Models

Model components that can be purchased,customized, and assembled into full-scale datamodels

Advantages

Reduced development time

Higher model quality and reliability

Two types:

Universal data models Industry-specific data models

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Chapter 2

Managing Projects Projecta planned undertaking of related activities to reach an

objective that has a beginning and an end

Involves use of review points for: Validation of satisfactory progress

Step back from detail to overall view

Renew commitment of stakeholders Incremental commitmentreview of systems development project

after each development phase with rejustification after each phase

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Chapter 2

Managing Projects: People Involved

Business analysts Systems analysts

Database analysts and data modelers

Users Programmers

Database architects

Data administrators

Project managers

Other technical experts30

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Chapter 2

Database Schema

Physical Schema Physical structurescovered in Chapters 5 and 6

Conceptual Schema

E-R modelscovered in Chapters 3 and 4 External Schema

User Views

Subsets of Conceptual Schema

Can be determined from business-function/data entitymatrices

DBA determines schema for different users

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Different people

have differentviews of the

databasethese

are the external

schema

The internal

schema is the

underlying

design andimplementation

Figure 2-7 Three-schema architecture

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Figure 2-8 Developing the three-tiered architecture

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Figure 2-9 Three-tiered client/server database architecture

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Chapter 2

Pine Valley Furniture

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Figure 2-12 Four relations (Pine Valley Furniture)

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Ch t 2

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Figure 2-12 Four relations (Pine Valley Furniture) (cont.)

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Chap 02 Corrected

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