The System Development Life Cycle

The creation of a database as an application information system must always follow the development life cycle through multiple stages of development.

Thus, a top-down approach to database development transforms business information requirements into an operational database. This approach is known as waterfall model and is depicted in the following figure. Database Development Life Cycle Strategy and Requirements Analysis In this phase we study and analyze the business requirements and decide which entities will compose our database. We interview users and managers in order to identify the information requirements according to our system strategy. We keep information for the future system specifications and choose the development data model for our database system. We transfer the business procedures into graphical representations, confirm and refine the model in connection to the system requirements and business needs and rules. Design We design the database based on the model that was developed in the strategy and requirements analysis phase. Logical database design is also referred to as the logical model. Thus, the relational database design is the process of arranging data into logical, organized groups of entities or objects which can easily be maintained. Especially the logical design of a relational database should reduce data repetition and completely eliminate it. This design approach follows a methodology (technique) that is called normalization. Normalization is the methodology that is used when designing and redesigning a relational database. Additionally, naming conventions should also be standard and logical. Implementation In this phase we write SQL code in order to create the tables of the database. The implementation stage contains the creation of the prototype system and all necessary work in order to build the documentation of the database application. This documentation includes user information, help text, and operations manuals to support the operation and the use of the system. Integration and Distribution The phase of integration and distribution of the database application refines the prototype. We transfer the database application into production with user acceptance testing, conversion of existing data, and parallel operations. We verify the results and make any modifications required in order to integrate the final operation and performance of the system. We distribute the database application to the users. Also, we test periodically the system and enhance its performance.