© 2005 by Prentice Hall 1 Chapter 2: The Database Development Process Modern Database Management 7 th Edition George Lamperti

© 2005 by Prentice Hall© 2005 by Prentice Hall 11

Chapter 2:Chapter 2: The Database The Database

Development Process Development Process

Modern Database Modern Database ManagementManagement

77thth Edition EditionGeorge LampertiGeorge Lamperti

22© 2005 by Prentice Hall© 2005 by Prentice HallChapter 2

ObjectivesObjectives Definition of termsDefinition of terms Describe Describe system development life cyclesystem development life cycle Explain Explain prototypingprototyping approach approach Explain roles of individualsExplain roles of individuals Explain three-schema approachExplain three-schema approach Explain role of packaged data modelsExplain role of packaged data models Explain three-tiered architecturesExplain three-tiered architectures Draw simple data modelsDraw simple data models


Enterprise Data ModelEnterprise Data Model

First step in database developmentFirst step in database development Specifies scope and general contentSpecifies scope and general content Overall picture of organizational data at Overall picture of organizational data at

high level of abstractionhigh level of abstraction Entity-relationship diagramEntity-relationship diagram Descriptions of entity typesDescriptions of entity types Relationships between entitiesRelationships between entities Business rulesBusiness rules


Figure 2-1 Segment from enterprise data model (Pine Valley Furniture Company) [simplified E-R diagram, repeat of figure 1.3]

Enterprise data model describes the high-level entities in an organization and the relationship between these entities

Homework Assignment 2-1


Information Systems Information Systems ArchitectureArchitecture

(ISA)(ISA) Conceptual blueprint for organization’s desired Conceptual blueprint for organization’s desired

information systems structureinformation systems structure Consists of:Consists of:

Data (e.g. Enterprise Data Model – simplified ER Diagram)Data (e.g. Enterprise Data Model – simplified ER Diagram) Processes – data flow diagrams, process decomposition, Processes – data flow diagrams, process decomposition,

etc.etc. Data Network – topology diagram (like fig 1.9)Data Network – topology diagram (like fig 1.9) People – people management using project management People – people management using project management

tools (Gantt charts, etc.)tools (Gantt charts, etc.) Events and points in time (when processes are Events and points in time (when processes are

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


Information EngineeringInformation Engineering A data-oriented methodology to create and A data-oriented methodology to create and

maintain information systemsmaintain information systems Top-down planning: a generic IS planning Top-down planning: a generic IS planning

methodology for obtaining a broad methodology for obtaining a broad understanding of the IS needed by the understanding of the IS needed by the entire organizationentire organization

Four steps to Top-Down planning:Four steps to Top-Down planning: PlanningPlanning AnalysisAnalysis DesignDesign ImplementationImplementation


Information Systems Information Systems PlanningPlanning

(Table 2-1) (Table 2-1) Purpose: align information Purpose: align information

technology with organization’s technology with organization’s business strategiesbusiness strategies

Three steps:Three steps:1.1. Identify strategic planning factors Identify strategic planning factors

2.2. Identify corporate planning objectsIdentify corporate planning objects

3.3. Develop enterprise modelDevelop enterprise model


Identify Strategic Planning Identify Strategic Planning Factors (Table 2-2)Factors (Table 2-2)

Organization goalsOrganization goals – what we hope to – what we hope to accomplishaccomplish

Critical success factorsCritical success factors – what MUST – what MUST work in order for us to survivework in order for us to survive

Problem areasProblem areas – weaknesses we now – weaknesses we now havehaveHomework Assignment 2-2


Identify Corporate Planning Identify Corporate Planning Objects (Table 2-3)Objects (Table 2-3)

Organizational units – departmentsOrganizational units – departments Organizational locationsOrganizational locations Business functions – groups of Business functions – groups of

business processesbusiness processes Entity types – the things we are Entity types – the things we are

trying to model for the databasetrying to model for the database Information systems – application Information systems – application

programsprograms


Develop Enterprise ModelDevelop Enterprise Model

Functional decompositionFunctional decomposition See Figure 2-2See Figure 2-2

Enterprise data model Enterprise data model See Figure 2-1See Figure 2-1

Planning matrixes Planning matrixes See Figure 2-3See Figure 2-3


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

Decomposition -- breaking large tasks into smaller tasks in a hierarchical structure chart


Planning MatrixesPlanning Matrixes Describe relationships between Describe relationships between

planning objects in the organizationplanning objects in the organization Types of matrixes:Types of matrixes:

Function-to-data entityFunction-to-data entity Location-to-functionLocation-to-function Unit-to-functionUnit-to-function IS-to-data entityIS-to-data entity Supporting function-to-data entitySupporting function-to-data entity IS-to-business objectiveIS-to-business objective


Example business function-Example business function-to-data entity matrix (Fig. 2-to-data entity matrix (Fig. 2-

3)3)

Business Planning X X X XProduct Development X X X XMaterials Management X X X X X XOrder Fulfillment X X X X X X X X XOrder Shipment X X X X X XSales Summarization X X X X XProduction Operations X X X X X X XFinance and Accounting X X X X X X X X

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BusinessFunction (users)

Data Entity Types


Two Approaches to Two Approaches to Database and IS Database and IS

DevelopmentDevelopment SDLCSDLC System Development Life CycleSystem Development Life Cycle Detailed, well-planned development processDetailed, well-planned development process Time-consuming, but comprehensiveTime-consuming, but comprehensive Long development cycleLong development cycle

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

new prototype versionsnew prototype versions


Systems Development Life Cycle Systems Development Life Cycle (Figures 2-4, 2-5)(Figures 2-4, 2-5)

Project Identification and Selection

Project Initiation and Planning

Analysis

Physical Design

Implementation

Maintenance

Logical Design


Systems Development Life Cycle (cont.) Systems Development Life Cycle (cont.)

(Figures 2-4, 2-5)(Figures 2-4, 2-5)

Maintenance

Purpose --preliminary understandingDeliverable –request for project

Database activity – enterprise modeling



Analysis

Physical Design

Implementation

Maintenance

Logical Design



Systems Development Life Cycle (cont.) Systems Development Life Cycle (cont.)

(figures 2-4, 2-5)(figures 2-4, 2-5)Purpose – state business situation and solutionDeliverable – request for analysis

Database activity – conceptual data modeling



Analysis

Physical Design

Implementation

Maintenance

Logical Design



Systems Development Life Cycle Systems Development Life Cycle (cont.)(cont.)

(figures 2-4, 2-5)(figures 2-4, 2-5)Purpose – thorough analysisDeliverable – functional system specifications

Database activity – conceptual data modeling



Analysis

Physical Design

Implementation

Maintenance

Logical Design

Analysis


Systems Development Life Cycle Systems Development Life Cycle (cont.) (figures 2-4, 2-5)(cont.) (figures 2-4, 2-5)

Maintenance

Purpose – information requirements structureDeliverable – detailed design specifications

Database activity – logical database design



Analysis

Physical Design

Implementation

Maintenance

Logical DesignLogical Design



(figures 2-4, 2-5)(figures 2-4, 2-5)Purpose – develop technology specsDeliverable – program/data structures, technology purchases, organization redesigns

Database activity – physical database design



Analysis

Physical Design

Implementation

Maintenance

Logical Design

Physical Design



(figures 2-4, 2-5)(figures 2-4, 2-5)Purpose – programming, testing, training, installation, documentingDeliverable – operational programs, documentation, training materials

Database activity – database implementation



Analysis

Physical Design

Implementation

Maintenance

Logical Design

Implementation



(figures 2-4, 2-5)(figures 2-4, 2-5)Purpose – monitor, repair, enhanceDeliverable – periodic audits

Database activity – database maintenance



Analysis

Physical Design

Implementation

Maintenance

Logical Design

Maintenance







Packaged Data ModelsPackaged Data Models

Model components that can be purchased, Model components that can be purchased, customized, and assembled into full-scale customized, and assembled into full-scale data modelsdata models

AdvantagesAdvantages Reduced development timeReduced development time Higher model quality and reliabilityHigher model quality and reliability

Two types:Two types: Universal data modelsUniversal data models Industry-specific data modelsIndustry-specific data models


CASECASE Computer-Aided Software Engineering Computer-Aided Software Engineering

(CASE) – software tools providing (CASE) – software tools providing automated support for systems automated support for systems developmentdevelopment

Three database features:Three database features: Data modeling – entity-relationship diagramsData modeling – entity-relationship diagrams Code generation – SQL code for table creationCode generation – SQL code for table creation Repositories – knowledge base of enterprise Repositories – knowledge base of enterprise

informationinformation


Managing ProjectsManaging Projects Project – a planned undertaking of related Project – a planned undertaking of related

activities to reach an objective that has a activities to reach an objective that has a beginning and an endbeginning and an end

Involves use of review points for:Involves use of review points for: Validation of satisfactory progressValidation of satisfactory progress Step back from detail to overall viewStep back from detail to overall view Renew commitment of stakeholdersRenew commitment of stakeholders

Incremental commitment – review of Incremental commitment – review of systems development project after each systems development project after each development phase with rejustification after development phase with rejustification after each phaseeach phase


Managing Projects: Managing Projects: People InvolvedPeople Involved

Systems analystsSystems analysts Database analystsDatabase analysts UsersUsers ProgrammersProgrammers Database/data administratorsDatabase/data administrators Systems programmers, network Systems programmers, network

administrators, testers, technical administrators, testers, technical writerswriters


Figure 2-8a Gantt Chart

Shows time estimates of tasks


Figure 2-8b PERT chart

Shows dependencies between tasks


Database SchemaDatabase Schema Physical Schema Physical Schema

Physical structures – covered in chapters 5 and 6Physical structures – covered in chapters 5 and 6 Conceptual SchemaConceptual Schema

E-R models – covered in chapters 3 and 4E-R models – covered in chapters 3 and 4 External SchemaExternal Schema

User ViewsUser Views Subsets of Conceptual SchemaSubsets of Conceptual Schema Can be determined from business-function/data Can be determined from business-function/data

entity matricesentity matrices DBA determines schema for different usersDBA determines schema for different users


Different people have different views of the database…these are the external schema

The internal schema is the underlying design and implementation


Figure 2-11 Three-tiered client/server database architecture


Pine Valley FurniturePine Valley Furniture

Preliminary data model(Figure 2-12)

Homework Assignment 1-2



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© 2005 by Prentice Hall 1 Chapter 2: The Database Development Process Modern Database Management 7 th Edition George Lamperti