1. Chapter 2:The Database Development ProcessModern Database Management 7 thEdition Jeffrey A. Hoffer, Mary B. Prescott,Fred R. McFadden

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

Draw simple data models

3. 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

4. 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 5. Information Systems Architecture (ISA)

Conceptual blueprint for organizations desired information systems structure

Consists of:

• Data (e.g. Enterprise Data Model simplified ER Diagram)

• Processes data flow diagrams, process decomposition, etc.

• Data Network topology diagram (like fig 1.9)

• People people management using project management tools (Gantt charts, etc.)

• Events and points in time (when processes are performed)

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

6. Information Engineering

A data-oriented methodology to create and maintain information systems

Top-down planning: a generic IS planning methodologyfor obtaining a broad understanding of the IS needed by the entire organization

Four steps to Top-Down planning:

• Planning

• Analysis

• Design

• Implementation

7. Information Systems Planning(Table 2-1)

Purpose: align information technology with organizations business strategies

Three steps:

• • Identify strategic planning factors

• • Identify corporate planning objects

• • Develop enterprise model

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

Organization goals what we hope to accomplish

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

Problem areas weaknesses we now have

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

Organizational units departments

Organizational locations

Business functions groups of business processes

Entity types the things we are trying to model for the database

Information systems application programs

10. Develop Enterprise Model

Functional decomposition

• See Figure 2-2

Enterprise data model

• See Figure 2-1

Planning matrixes

• See Figure 2-3

11. 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 12. 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

13. Example business function-to-data entity matrix (Fig. 2-3) Business Planning XX XX Product Development XXXX Materials Management XXXXXX Order Fulfillment XXXXXXXXX Order Shipment XXXXXX Sales Summarization XXXXX Production Operations XXXXXXX Finance and Accounting XXXXXXXX Customer Product Raw Material OrderWork Center Work Order Invoice Equipment Employee Business Function (users) Data Entity Types 14. 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

15. Systems Development Life Cycle(Figures 2-4, 2-5) Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 16. Systems Development Life Cycle (cont.)(Figures 2-4, 2-5) Maintenance Purpose --preliminary understanding Deliverable request for projectDatabase activity enterprise modeling Project Identification and Selection Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 17. Systems Development Life Cycle (cont.)(figures 2-4, 2-5) Purpose state business situation and solution Deliverable request for analysis Database activity conceptual data modeling Project Initiation and Planning Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 18. Systems Development Life Cycle(cont.) (figures 2-4, 2-5) Purpose thorough analysis Deliverable functional system specifications Database activity conceptual data modeling Analysis Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 19. Systems Development Life Cycle(cont.) (figures 2-4, 2-5) Maintenance Purpose information requirements structure Deliverable detailed design specifications Database activity logical database design Logical Design Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 20. Systems Development Life Cycle(cont.) (figures 2-4, 2-5) Purpose develop technology specs Deliverable program/data structures, technology purchases, organization redesigns Database activity physical database design Physical Design Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 21. Systems Development Life Cycle(cont.) (figures 2-4, 2-5) Purpose programming, testing, training, installation, documenting Deliverable operational programs, documentation, training materials Database activity database implementation Implementation Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 22. Systems Development Life Cycle(cont.) (figures 2-4, 2-5) Purpose monitor, repair, enhance Deliverable periodic audits Database activity database maintenance Maintenance Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design 23. 24. 25. 26. 27. 28. Packaged Data Models

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

Advantages

• Reduced development time

• Higher model quality and reliability

Two types:

• Universal data models

• Industry-specific data models

29. CASE

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

Three database features:

• Data modeling entity-relationship diagrams

• Code generation SQL code for table creation

• Repositories knowledge base of enterprise information

30. Managing Projects

Project a 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 commitment review of systems development project after each development phase with rejustification after each phase

31. Managing Projects:People Involved

Systems analysts

Database analysts

Users

Programmers

Database/data administrators

Systems programmers, network administrators, testers, technical writers

32. Figure 2-8a Gantt Chart Shows time estimates of tasks 33. Figure 2-8b PERT chart Shows dependencies between tasks 34. Database Schema

Physical Schema

• Physical structures covered in chapters 5 and 6

Conceptual Schema

• E-R models covered in chapters 3 and 4

External Schema

• User Views

• Subsets of Conceptual Schema

• Can be determined from business-function/data entity matrices

• DBA determines schema for different users

35. Different people have different views of the databasethese are the external schema The internal schema is the underlying design and implementation 36. Figure 2-11 Three-tiered client/server database architecture 37. Pine Valley Furniture Preliminary data model (Figure 2-12) 38.