1. The database development process
Chapter 2
The database development process

2. Information Systems Architecture
A conceptual blueprint or plan that expresses the desired future structure for the information systems in an organization.

3. Architecture example Data validation and retention Integrated
data warehouse
Access
analysis and
presentation
tools
Information
delivery system
CIM
Business Operations
EDI
Customers
& Suppliers
External Events
External
database
access
Dialogue
Decision makers
Customers, Suppliers

4. A more sophisticated example...

5. Information Systems Architecture
Key components:
data
processes which manipulate data
network which transports data
people who perform processes and send and receive data
events and points in time when processes are performed
reasons for events and rules which govern data processing

6. Information Engineering
An Information Systems Architecture is developed by IS planners following a particular methodology such as Information Engineering.

7. Information Engineering
Data-oriented methodology
Uses top-down planning in which specific information systems are deduced from a broad understanding of organization’s information needs, rather than relying on specific user information requests
Offers perspective on relationship of information systems to business objectives

8. Top-Down vs. Bottom-Up Top-Down Planning:
A methodology that attempts to gain a broad understanding of the information system needs of the entire organization
Bottom-Up Planning:
A methodology that identifies and defines IS development projects based upon solving operational business problems or taking advantage of business opportunities

9. The big picture... Information engineering
Information systems planning
Identify strategic planning factors (goals, CSFs, problem areas)
IT vision
Identify corporate planning objectives
Information system architecture
Develop enterprise model
Systems analysis
Systems design
implementation

10. Systems Development Life Cycle
Project Identification & Selection
Project Initiation & Planning
Analysis
Logical Design
Physical Design
Implementation
Maintenance

11. Database Development Activities
Database SDLC
SDLC
Database Development Activities
Identify Project
Enterprise
Modeling
Initiate and Plan
Conceptual
Data Modeling
Analyze
Logical
DB Design
Logical Design
Physical DB
Design/Creation
Physical Design DB
Implementation
Implementation DB
Maintenance
Maintenance

12. Planning Matrixes
Show interrelationships between objects. Among the possibilities:
Location-to-Function
Unit-to-Function
Information System-to-Data Entity
Supporting Function-to-Data Entity
Information System-to-Objective

13. Business Function-to-Data Entity Planning Matrix

14. Information System-to-Objective Planning Matrix

15. Functional Decomposition

16. Enterprise Data Modeling
The first step in database development, in which the scope and general contents of organizational databases are specified.

17. Enterprise Data Model A model which includes:
overall range of organizational databases
general contents of organizational databases
Built as part of IS planning for the organization and not the design of a particular database
One part of an organization’s overall information systems architecture (ISA)

18. Conceptual Database Modeling
Determine user requirements
Determine business rules
Build conceptual data model
outcome is an entity-relationship diagram or similar communication tool
population of repository
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation DB
Implementation DB
Maintenance

19. Logical Database Design
Select logical database model
commit to a database alternative
Map Entity-Relationship Diagrams
Normalize data structures
Specify business rules
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation DB
Implementation DB
Maintenance

20. Physical Database Design
Select DBMS
Select storage devices
Determine access methods
Design files and indexes
Determine database distribution
Specify update strategies
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation DB
Implementation DB
Maintenance

21. Database implementation
Code and test database processing programs
Complete documentation
Install database and convert data
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation DB
Implementation DB
Maintenance

22. Database Maintenance
Analyze database and applications to ensure evolving information requirements are being met
Tune database for improved performance
Fix errors
Provide data recovery when needed
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation DB
Implementation DB
Maintenance

23. Documentation
most formal development methodologies are documentation based
helps managers monitor progress and quality of project
facilitates communication between team members
includes models
various stages are not complete until documentation is accepted

24. Some Keys to Success... accurate requirements definition commitment
effective change management
manageable size
champion

25. So …

26. Three Schema Architecture for Database Development
Conceptual Schema
Analysis project phase
External Schema
Analysis and Logical Design phases
(subset of conceptual schema)
Internal Schema
Physical Design phase

27. 3-schema architecture

28. Conceptual Schema
Describes the logical structure of the entire database
Independent of a specific DBMS
Avoids details of physical design
Stated in
ERDs
metadata

29. External Schema Also called a user view
Specifications include screen formats, report formats, transaction definitions

30. Physical Schema Describes physical structure of entire database
Specifies how data from a conceptual schema are stored in secondary memory
Sometimes called internal schema
Specifications include physical file and data structures, storage organization, and index structures

31. 3-schema development process

32. Rapid application development
design methodology which speeds systems delivery through a combination of speedy design iterations, data modeling, user/developer teamwork, and automated development tools.
encompasses a set of techniques that can be used to build complex, strategic, and mission-critical applications in months rather than years

33. RAD

34. The RAD lifecycle requirements planning
conduct joint requirement planning workshop
design
conduct JAD workshop
construction
members of team monitor evolution, system is prototyped
cutover
installation

35. Within the time box... Requirements planning User design
construction phase
build and evolve prototype
User review
time box
request for change
Evaluate system
cutover

36. Barriers to overcome... poor training/ tools
reluctance to leave old methods behind
mindset that RAD is not adequate for large-scale systems development
speedy delivery does not mean low quality
“creeping functionality”