Discuss in detail the design concepts.

Abstraction

• Functional abstraction
• Data abstraction
• Control abstraction

Information hiding

• Each unit in the system hides the internal facts of its processing activities and modules communicate only through over defined interfaces.

Structure

• It allows the breakup of a large system into smaller, more manageable units with well defined relationships to the other units in a system.
• Network is the most common form of structure.

Hierarchical Structures/Structure Charts

• It provides the structure of subroutines in a system, the data passed through routines, can be indicated on the arcs connecting routines.

Modularity

• Modular system has a well-defined, manageable units with well defined interfaces among units.

Concurrency

• Individual processes that can be activated concurrently if multiple processors are available.

Coupling and Cohesion

• Data coupling - The data coupling is achievable by parameter passing or data interaction.
• Control coupling - The modules share related control data in control coupling.
• Common coupling - The global data is shared among modules.
• Content coupling - Content coupling occurs when one module try to use of data or control information controlled in another module.