Information Technology Reference
In-Depth Information
oriented approach is to model the decision support system through the use of
flexible modeling tools such as an entity relationship diagram (ERD). The third
step in data-oriented approach is to divide each criterion into its attributes. The
fourth step is to break down the attributes identified above into their most fun-
damental data components.
7.3.3 Creating the Data Dictionary
Once the data is identified for a system using either process-oriented or data-
oriented approach, systems professionals use the information to create a data
dictionary. The data dictionary includes the following attributes:
• Size
• Type
• Description
• Limits and exceptions
• Ranges
• Security level
• Access privileges
Three aspects of data dictionaries are:
• Changes: The data dictionary is not a static document that is never changed
• Description: Attributes names must describe data defined fully
• Order: Attributes should be arranged in some form of standard order
7.4 Object-Oriented Approach
The design process is concerned with describing how a requirement is to be met by
the design product. In other words, design is a creative process of transforming the
problem into a solution. Good design is the key to effective engineering. However, it
is not possible to formalize the design process in any engineering discipline. It must
be practiced and learnt by experience and study of existing system (Turner et al.
2003
). Software design can be viewed in the same way. We use the requirements
specification to define the problem. Then, we declare something to be a solution to
the problem if it satisfies all the requirements in the specification. The nature of the
solution may change as the solution is described or implemented (Pfleeger
2001
).
Object-oriented design is a design strategy based on information hiding. It
differs from the functional approach to design in that it views a software system as
a set of interactive objects with its own private state, rather than as a set of
functions that share a global state. Outside the business systems domain it is the
