1. © 2007 by Prentice Hall 1 Chapter 2: The Database Development Process Modern Database Management 8 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden

2. © 2007 by Prentice Hall Chapter 2 2 Objectives Definition of terms Definition of terms Describe system development life cycle Describe system development life cycle Explain prototyping approach Explain prototyping approach Explain roles of individuals Explain roles of individuals Explain three-schema approach Explain three-schema approach Explain role of packaged data models Explain role of packaged data models Explain three-tiered architectures Explain three-tiered architectures Explain scope of database design projects Explain scope of database design projects Draw simple data models Draw simple data models

3. © 2007 by Prentice Hall Chapter 2 3 Enterprise Data Model First step in database development First step in database development Specifies scope and general content Specifies scope and general content Overall picture of organizational data at high level of abstraction Overall picture of organizational data at high level of abstraction Entity-relationship diagram Entity-relationship diagram Descriptions of entity types Descriptions of entity types Relationships between entities Relationships between entities Business rules Business rules

4. © 2007 by Prentice Hall Chapter 2 4 Figure 2-1 Segment from enterprise data model Enterprise data model describes the high- level entities in an organization and the relationship between these entities

5. © 2007 by Prentice Hall Chapter 2 5 Information Systems Architecture (ISA) Conceptual blueprint for organization’s desired information systems structure Conceptual blueprint for organization’s desired information 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, etc. Processes – data flow diagrams, process decomposition, etc. Data Network – topology diagram (like Fig 1-9) Data Network – topology diagram (like Fig 1-9) People – people management using project management tools (Gantt charts, etc.) People – people management using project management tools (Gantt charts, etc.) Events and points in time (when processes are performed) Events and points in time (when processes are performed) Reasons for events and rules (e.g., decision tables) Reasons for events and rules (e.g., decision tables)

6. © 2007 by Prentice Hall Chapter 2 6 Information Engineering A data-oriented methodology to create and maintain information systems A data-oriented methodology to create and maintain information systems Top-down planning–a generic IS planning methodology for obtaining a broad understanding of the IS needed by the entire organization Top-down planning–a generic IS planning methodology for obtaining a broad understanding of the IS needed by the entire organization Four steps to Top-Down planning: Four steps to Top-Down planning: Planning Planning Analysis Analysis Design Design Implementation Implementation

7. © 2007 by Prentice Hall Chapter 2 7 Information Systems Planning (Table 2-1) Purpose – align information technology with organization’s business strategies Purpose – align information technology with organization’s business strategies Three steps: Three steps: 1. Identify strategic planning factors 2. Identify corporate planning objects 3. Develop enterprise model

8. © 2007 by Prentice Hall Chapter 2 8 Identify Strategic Planning Factors (Table 2-2) Organization goals–what we hope to accomplish Organization goals–what we hope to accomplish Critical success factors–what MUST work in order for us to survive Critical success factors–what MUST work in order for us to survive Problem areas–weaknesses we now have Problem areas–weaknesses we now have

9. © 2007 by Prentice Hall Chapter 2 9 Identify Corporate Planning Objects (Table 2-3) Organizational units–departments Organizational units–departments Organizational locations Organizational locations Business functions–groups of business processes Business functions–groups of business processes Entity types–the things we are trying to model for the database Entity types–the things we are trying to model for the database Information systems–application programs Information systems–application programs

10. © 2007 by Prentice Hall Chapter 2 10 Develop Enterprise Model Functional decomposition Functional decomposition Iterative process breaking system description into finer and finer detail Iterative process breaking system description into finer and finer detail Enterprise data model Enterprise data model Planning matrixes Planning matrixes Describe interrelationships Describe interrelationships between planning objects

11. © 2007 by Prentice Hall Chapter 2 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. © 2007 by Prentice Hall Chapter 2 12 Planning Matrixes Describe relationships between planning objects in the organization Describe relationships between planning objects in the organization Types of matrixes: Types of matrixes: Function-to-data entity Function-to-data entity Location-to-function Location-to-function Unit-to-function Unit-to-function IS-to-data entity IS-to-data entity Supporting function-to-data entity Supporting function-to-data entity IS-to-business objective IS-to-business objective

13. © 2007 by Prentice Hall Chapter 2 13 Example business function-to- data entity matrix (Fig. 2-3)

14. © 2007 by Prentice Hall Chapter 2 14 Two Approaches to Database and IS Development SDLC SDLC System Development Life Cycle System Development Life Cycle Detailed, well-planned development process Detailed, well-planned development process Time-consuming, but comprehensive Time-consuming, but comprehensive Long development cycle Long development cycle Prototyping Prototyping 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 prototype Define database during development of initial prototype Repeat implementation and maintenance activities with new prototype versions Repeat implementation and maintenance activities with new prototype versions

15. © 2007 by Prentice Hall Chapter 2 15 Systems Development Life Cycle (see also Figures 2.4, 2.5) Planning Analysis Physical Design Implementation Maintenance Logical Design

16. © 2007 by Prentice Hall Chapter 2 16 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Planning – Purpose – preliminary understanding – Deliverable – request for study – Database activity – enterprise modeling and early conceptual data modeling

17. © 2007 by Prentice Hall Chapter 2 17 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Analysis Purpose–thorough requirements analysis and structuring Deliverable–functional system specifications Database activity–Thorough and integrated conceptual data modeling

18. © 2007 by Prentice Hall Chapter 2 18 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Purpose–information requirements elicitation and structure Deliverable–detailed design specifications Database activity– logical database design (transactions, forms, displays, views, data integrity and security)

19. © 2007 by Prentice Hall Chapter 2 19 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Physical Design Purpose–develop technology and organizational specifications Deliverable–program/data structures, technology purchases, organization redesigns Database activity– physical database design (define database to DBMS, physical data organization, database processing programs)

20. © 2007 by Prentice Hall Chapter 2 20 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Implementation Purpose–programming, testing, training, installation, documenting Deliverable–operational programs, documentation, training materials Database activity– database implementation, including coded programs, documentation, installation and conversion

21. © 2007 by Prentice Hall Chapter 2 21 Systems Development Life Cycle (see also Figures 2.4, 2.5) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Maintenance Purpose–monitor, repair, enhance Deliverable–periodic audits Database activity– database maintenance, performance analysis and tuning, error corrections

22. © 2007 by Prentice Hall Chapter 2 22 Prototyping Database Methodology (Figure 2.6)

23. © 2007 by Prentice Hall Chapter 2 23 Prototyping Database Methodology (Figure 2.6) (cont.)

24. © 2007 by Prentice Hall Chapter 2 24 Prototyping Database Methodology (Figure 2.6) (cont.)

25. © 2007 by Prentice Hall Chapter 2 25 Prototyping Database Methodology (Figure 2.6) (cont.)

26. © 2007 by Prentice Hall Chapter 2 26 Prototyping Database Methodology (Figure 2.6) (cont.)

27. © 2007 by Prentice Hall Chapter 2 27 CASE Computer-Aided Software Engineering (CASE)–software tools providing automated support for systems development Computer-Aided Software Engineering (CASE)–software tools providing automated support for systems development Three database features: Three database features: Data modeling–drawing entity-relationship diagrams Data modeling–drawing entity-relationship diagrams Code generation–SQL code for table creation Code generation–SQL code for table creation Repositories–knowledge base of enterprise information Repositories–knowledge base of enterprise information

28. © 2007 by Prentice Hall Chapter 2 28 Packaged Data Models Model components that can be purchased, customized, and assembled into full-scale data models Model components that can be purchased, customized, and assembled into full-scale data models Advantages Advantages Reduced development time Reduced development time Higher model quality and reliability Higher model quality and reliability Two types: Two types: Universal data models Universal data models Industry-specific data models Industry-specific data models

29. © 2007 by Prentice Hall Chapter 2 29 Managing Projects Project–a planned undertaking of related activities to reach an objective that has a beginning and an end Project–a planned undertaking of related activities to reach an objective that has a beginning and an end Involves use of review points for: Involves use of review points for: Validation of satisfactory progress Validation of satisfactory progress Step back from detail to overall view Step back from detail to overall view Renew commitment of stakeholders Renew commitment of stakeholders Incremental commitment–review of systems development project after each development phase with rejustification after each phase Incremental commitment–review of systems development project after each development phase with rejustification after each phase

30. © 2007 by Prentice Hall Chapter 2 30 Managing Projects: People Involved Business analysts Business analysts Systems analysts Systems analysts Database analysts and data modelers Database analysts and data modelers Users Users Programmers Programmers Database architects Database architects Data administrators Data administrators Project managers Project managers Other technical experts Other technical experts

31. © 2007 by Prentice Hall Chapter 2 31 Database Schema Physical Schema Physical Schema Physical structures–covered in Chapters 5 and 6 Physical structures–covered in Chapters 5 and 6 Conceptual Schema Conceptual Schema E-R models–covered in Chapters 3 and 4 E-R models–covered in Chapters 3 and 4 External Schema External Schema User Views User Views Subsets of Conceptual Schema Subsets of Conceptual Schema Can be determined from business-function/data entity matrices Can be determined from business-function/data entity matrices DBA determines schema for different users DBA determines schema for different users

32. © 2007 by Prentice Hall Chapter 2 32 Different people have different views of the database…these are the external schema The internal schema is the underlying design and implementation Figure 2-7 Three-schema architecture

33. © 2007 by Prentice Hall Chapter 2 33 Figure 2-8 Developing the three-tiered architecture

34. © 2007 by Prentice Hall Chapter 2 34 Figure 2-9 Three-tiered client/server database architecture

35. © 2007 by Prentice Hall Chapter 2 35 Pine Valley Furniture Segment of project data model (Figure 2-11)

36. © 2007 by Prentice Hall Chapter 2 36 Figure 2-12 Four relations (Pine Valley Furniture)

37. © 2007 by Prentice Hall Chapter 2 37 Figure 2-12 Four relations (Pine Valley Furniture) (cont.)