Database Life Cycle (DBLC)
The Database Life Cycle (DBLC) contains six phases, as shown in the following
Figure: database initial study, database design, implementation and loading, testing
and evaluation, operation, and maintenance and evolution.
The Database Initial Study:
In the Database initial study, the designer must examine the current
system’s operation within the company and determine how and why the
current system fails. The overall purpose of the database initial study is to:
• Analyze the company situation.
• Define problems and constraints.
• Define objectives.
• Define scope and boundaries.
, a. Analyze the Company Situation:
The company situation describes the general conditions in which a company
operates, its organizational structure, and its mission. To analyze the
company situation, the database designer must discover what the company’s
operational components are, how they function, and how they interact.
b. Define Problems and Constraints:
The designer has both formal and informal sources of information. The
process of defining problems might initially appear to be unstructured.
Company end users are often unable to describe precisely the larger scope
of company operations or to identify the real problems encountered during
company operations.
c. Define Objectives:
A proposed database system must be designed to help solve at least the
major problems identified during the problem discovery process. In any
case, the database designer must begin to address the following questions:
• What is the proposed system’s initial objective?
• Will the system interface with other existing or future systems in the
company?
• Will the system share the data with other systems or users?
d. Define Scope and Boundaries:
The designer must recognize the existence of two sets of limits: scope and
boundaries. The system’s scope defines the extent of the design according to
operational requirements. Will the database design encompass the entire
organization, one or more departments within the organization, or one or
more functions of a single department? Knowing the scope helps in defining
the required data structures, the type and number of entities, the physical
size of the database, and so on.
The proposed system is also subject to limits known as boundaries, which
are external to the system. Boundaries are also imposed by existing
hardware and software.
The Database Life Cycle (DBLC) contains six phases, as shown in the following
Figure: database initial study, database design, implementation and loading, testing
and evaluation, operation, and maintenance and evolution.
The Database Initial Study:
In the Database initial study, the designer must examine the current
system’s operation within the company and determine how and why the
current system fails. The overall purpose of the database initial study is to:
• Analyze the company situation.
• Define problems and constraints.
• Define objectives.
• Define scope and boundaries.
, a. Analyze the Company Situation:
The company situation describes the general conditions in which a company
operates, its organizational structure, and its mission. To analyze the
company situation, the database designer must discover what the company’s
operational components are, how they function, and how they interact.
b. Define Problems and Constraints:
The designer has both formal and informal sources of information. The
process of defining problems might initially appear to be unstructured.
Company end users are often unable to describe precisely the larger scope
of company operations or to identify the real problems encountered during
company operations.
c. Define Objectives:
A proposed database system must be designed to help solve at least the
major problems identified during the problem discovery process. In any
case, the database designer must begin to address the following questions:
• What is the proposed system’s initial objective?
• Will the system interface with other existing or future systems in the
company?
• Will the system share the data with other systems or users?
d. Define Scope and Boundaries:
The designer must recognize the existence of two sets of limits: scope and
boundaries. The system’s scope defines the extent of the design according to
operational requirements. Will the database design encompass the entire
organization, one or more departments within the organization, or one or
more functions of a single department? Knowing the scope helps in defining
the required data structures, the type and number of entities, the physical
size of the database, and so on.
The proposed system is also subject to limits known as boundaries, which
are external to the system. Boundaries are also imposed by existing
hardware and software.
