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

2. © 2005 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 Draw simple data models Draw simple data models

3. © 2005 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. © 2005 by Prentice Hall Chapter 2 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 Homework Assignment 2-1

5. © 2005 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. © 2005 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. © 2005 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. © 2005 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 Homework Assignment 2-2

9. © 2005 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. © 2005 by Prentice Hall Chapter 2 10 Develop Enterprise Model Functional decomposition Functional decomposition See Figure 2-2 See Figure 2-2 Enterprise data model Enterprise data model See Figure 2-1 See Figure 2-1 Planning matrixes Planning matrixes See Figure 2-3 See Figure 2-3

11. © 2005 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. © 2005 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. © 2005 by Prentice Hall Chapter 2 13 Example business function-to- data entity matrix (Fig. 2-3) Business PlanningX X X X Product Development X X X X Materials Management X X X X X X Order FulfillmentX X X X X X X X X Order ShipmentX X X X X X Sales SummarizationX X X X X Production Operations X X X X X X X Finance and AccountingX X X X X X X X Customer Product Raw Material Order Work Center Work Order Invoice Equipment Employee Business Function (users) Data Entity Types

14. © 2005 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. © 2005 by Prentice Hall Chapter 2 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. © 2005 by Prentice Hall Chapter 2 16 Systems Development Life Cycle (cont.) (Figures 2-4, 2-5) Maintenance Purpose --preliminary understanding Deliverable –request for project Database activity – enterprise modeling Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Project Identification and Selection

17. © 2005 by Prentice Hall Chapter 2 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 Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Project Initiation and Planning

18. © 2005 by Prentice Hall Chapter 2 18 Systems Development Life Cycle (cont.) (figures 2-4, 2-5) Purpose – thorough analysis Deliverable – functional system specifications Database activity – conceptual data modeling Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Analysis

19. © 2005 by Prentice Hall Chapter 2 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 Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design

20. © 2005 by Prentice Hall Chapter 2 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 Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Physical Design

21. © 2005 by Prentice Hall Chapter 2 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 Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Implementation

22. © 2005 by Prentice Hall Chapter 2 22 Systems Development Life Cycle (cont.) (figures 2-4, 2-5) Purpose – monitor, repair, enhance Deliverable – periodic audits Database activity – database maintenance Project Identification and Selection Project Initiation and Planning Analysis Physical Design Implementation Maintenance Logical Design Maintenance

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28. © 2005 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. © 2005 by Prentice Hall Chapter 2 29 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 – entity-relationship diagrams Data modeling – 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

30. © 2005 by Prentice Hall Chapter 2 30 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

31. © 2005 by Prentice Hall Chapter 2 31 Managing Projects: People Involved Systems analysts Systems analysts Database analysts Database analysts Users Users Programmers Programmers Database/data administrators Database/data administrators Systems programmers, network administrators, testers, technical writers Systems programmers, network administrators, testers, technical writers

32. © 2005 by Prentice Hall Chapter 2 32 Figure 2-8a Gantt Chart Shows time estimates of tasks

33. © 2005 by Prentice Hall Chapter 2 33 Figure 2-8b PERT chart Shows dependencies between tasks

34. © 2005 by Prentice Hall Chapter 2 34 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

35. © 2005 by Prentice Hall Chapter 2 35 Different people have different views of the database…these are the external schema The internal schema is the underlying design and implementation

36. © 2005 by Prentice Hall Chapter 2 36 Figure 2-11 Three-tiered client/server database architecture

37. © 2005 by Prentice Hall Chapter 2 37 Pine Valley Furniture Preliminary data model (Figure 2-12) Homework Assignment 1-2

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39. © 2005 by Prentice Hall Chapter 2 39 Questions