Chapter 4: Database Application Development

System Development Life Cycle

Information System or IS is resources that enable the collection, management, control and dissemination of information throughout an organization. SDLC is a structured model that outlines the stages required to build an IS.

Database Development Life Cycle

• Database Initial Study
• Database Design
• Implementation and Loading
• Testing and Evaluation
• Operation
• Maintenance and Evolution

Database Initial Study

Initial study considers a statement of requirements and produces a specification. A specification is a formal representation of what the system should do. The purpose of an initial study is to collect requirements, define problems, define objectives, and define scope. Methods using during this stage include Interviewing end users, Questionnaires, and Direct observation.

• Analyze the company situation: When analyzing the company situation we need to identify functional and non-functional requirements. Function requirements describe the desired functionality like data entry, storage, and retrieval. Non-functional requirements specify the constraints and performance expectations.
• Define problems: When defining a problem, a problem is the difference between the actual situation and the desired situation.
• Define objectives: When defining objectives we need to answer the questions what is the system’s initial objective? and will it share data with existing or future systems?
• Define scope: defines the extent of the database design, and answers the questions will it cover the whole organization? part of an organization? part of a department?

Database Design

• Conceptual Database Design: constructs a model independent of all technical or physical considerations.
• Logical Database Design: constructs a model based on a specific data model independent of a particular DBMS and other physical considerations.
• Physical Database Design: construct an implementation of the database on a secondary storage device.