Design Concepts-Design Model
The design concepts provide
the software designer with a foundation from which more sophisticated methods
can be applied. A set of fundamental design concepts has evolved. They are:
Abstraction - Abstraction is the process or result of generalization by
reducing the information content of a concept or an observable phenomenon,
typically in order to retain only information which is relevant for a
Refinement - It is the process of elaboration. A hierarchy is developed by
decomposing a macroscopic statement of function in a step-wise fashion until
programming language statements are reached. In each step, one or several
instructions of a given program are decomposed into more detailed instructions.
Abstraction and Refinement are complementary concepts.
Modularity - Software architecture is divided into components called modules.
4. Software Architecture - It refers to the overall structure of the software and the ways in which that structure provides conceptual integrity for a system. A good software architecture will yield a good return on investment with respect to the desired outcome of the project, e.g. in terms of performance, quality, schedule and cost.
Control Hierarchy - A program structure that represents the
organization of a program component and implies a hierarchy of control.
Structural Partitioning - The program structure can be divided both
horizontally and vertically. Horizontal partitions define separate branches of
modular hierarchy for each major program function. Vertical partitioning
suggests that control and work should be distributed top down in the program
Data Structure - It is a representation of the logical relationship among
individual elements of data.
Software Procedure - It focuses on the processing of each modules
Information Hiding - Modules should be specified and designed so
that information contained within a module is inaccessible to other modules
that have no need for such information