Software Engineering

The term software engineering is composed of two words, software and engineering.

Software engineering is the branch of computer science that deals with the design, development, testing, and maintenance of software applications.

NEED OF SOFTWARE ENGINEERING
The need of software engineering arises because of higher rate of change in user requirements
and environment on which the software is working.
Large software – It is easier to build a wall than to a house or building, likewise, as the size
of software become large engineering has to step to give it a scientific process.
Scalability– If the software process were not based on scientific and engineering concepts, it
would be easier to re-create new software than to scale an existing one.

Cost– As hardware industry has shown its skills and huge manufacturing has lower down the
price of computer and electronic hardware. But the cost of software remains high if proper
process is not adapted.
Dynamic Nature– The always growing and adapting nature of software hugely depends upon
the environment in which the user works. If the nature of software is always changing, new
enhancements need to be done in the existing one. This is where software engineering plays a
good role.
Quality Management– Better process of software development provides better and quality
software product.

CHARACTERESTICS OF GOOD SOFTWARE
A software product can be judged by what it offers and how well it can be used. This
software must satisfy on the following grounds:
 Operational
 Transitional
 Maintenance
Well-engineered and crafted software is expected to have the following characteristics:
Operational: This tells us how well software works in operations. It can be measured on:
o Budget
o Usability
o Efficiency
o Correctness
o Functionality

o Dependability
o Security
o Safety
Transitional: This aspect is important when the software is moved from one platform to
another:
o Portability
o Interoperability
o Reusability
o Adaptability
Maintenance: This aspect briefs about how well a software has the capabilities to maintain
itself in the ever-changing environment:

o Modularity
o Maintainability
o Flexibility
o Scalability
In short, Software engineering is a branch of computer science, which uses well-defined
engineering concepts required to produce efficient, durable, scalable, in-budget and on-time
software products.

LAYERS OF SOFTWARE ENGINEERING