The document discusses the software design process, highlighting its importance within the software development life cycle (SDLC) and its phases: architectural, physical, and detailed design. It covers key concepts such as abstraction, information hiding, modularity, and the principles of coupling and cohesion, which aid in creating maintainable and scalable software. Additionally, it outlines various design methodologies, specifically function-oriented and object-oriented design, to structure software effectively.

1. Dr. V Nagesh
Professor & Head,
Department of Information Technology
MVGR College of Engineering

2.  Is the process of describing the blue print or
sketch of the final software product in the
form of a design model
 A software product is a collection of software
modules
 A module is a part of a software product
which has data and functions together and an
interface with other module to produce some
outcome

3.  A software design exists between requirements engineering
and programming.
 The software design process basically consists of three
design phases or design levels:
◦ Architectural design
◦ Physical design
◦ Detailed design
Architectural design
Architectural design
Architectural design

4.  Correctness
 Efficiency
 Understandability
 Maintainability
 Simplicity
 Correctness
 Completeness
 Verifiability
 Portability
 Modularity
 Reliability
 Reusability

5.  Software design is one of the important
phases of SDLC
 Common concepts of software design are:
◦ Abstraction
◦ Information hiding
◦ Functional decomposition
◦ Design strategies
◦ Modularity
◦ Modular design

6.  One of the most fundamental principles taken
into account in the software development
process
 Abstraction is a process of describing a
problem at a higher level of representation
without bothering about its internal details.
 Helps in maintenance phase to understand
and maintain the system

7.  Separates design from implementation
 Helps in problem understanding and maintenance
 Reduces complexity of modern computer
programming for software users and engineers
 Helps in organization that can be generalized for
recovering common problems and therefore it
promotes software reuse.
 Promotes scalability and helps in making early
design decisions.

8.  Concept of information hiding was initially
proposed by Parnas in 1972
 Is an important design principle which is expressed
through encapsulation and abstraction.
 Helps in modularization of software projects into
small components.

9.  Is a process of partitioning a large and complex
problem into small, manageable and
understandable pieces.
 Uses divide and conquer

10.  Top-down
 Bottom-up

11.  Measures the independency of the parts of a
system and enhances separation of concerns
 Enhances quality factors: portability, extensibility,
compatibility, scalability etc.
 Module contains data structure, I/O statements,
instructions and processing logic
 Called into one another

12.  Focuses on minimizing the interconnections
between modules
 An effective modular system has low coupling
and high cohesion
 Coupling: Is the strength of interconnection
between modules. It can be either loosely
coupled or tightly coupled
 Cohesion: Is the degree to which the
elements of a single module are functionally
related to achieve an objective.

13.  Message coupling
 Data coupling
 Stamp coupling
 Control coupling
 External coupling
 Common coupling
 Content coupling

14.  Functional cohesion
 Sequential cohesion
 Communication cohesion
 Procedural cohesion
 Temporal cohesion
 Logical cohesion
 Coincidental cohesion

15.  Used to propose a solution for the system in a
conceptual manner once all the requirements are
available.
 A design methodology provides the techniques and
guidelines for the design process of a system.
 The most popular design activities are:
◦ Function oriented design
◦ Object oriented design

16.  Structure chart