MELJUN CORTES Database Development Process

© 2005 by Prentice Hall© 2005 by Prentice Hall 11

Chapter 2:Chapter 2: The Database The Database

Development Process Development Process Modern Database ManagementModern Database Management

77thth Edition Edition

MELJUN CORTESMELJUN CORTES

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

ObjectivesObjectives Definition of termsDefinition of terms Describe system development life cycleDescribe system development life cycle Explain prototyping approachExplain prototyping 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


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 A data-oriented methodology to create

and maintain information systemsand maintain information systems Top-down planning: a generic IS Top-down planning: a generic IS

planning methodology for obtaining a planning methodology for obtaining a broad understanding of the IS needed broad understanding of the IS needed by the entire organizationby the entire 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 goals – what we hope to Organization goals – what we hope to accomplishaccomplish

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

Problem areas – weaknesses we now Problem areas – weaknesses we now havehave


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


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 Define database during development of initial

prototypeprototype Repeat implementation and maintenance Repeat implementation and maintenance

activities with new prototype versionsactivities with new 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







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

related activities to reach an related activities to reach an objective that has a beginning and objective that has a beginning and an endan 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 systems development project after each development phase with each development phase with rejustification after each phaserejustification after each 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


Documents

MELJUN CORTES Database Development Process