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Video Title: Testing Levels
Description: Testing Levels
Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm
Lecture By: Mr. Arnab Chakraborty, Tutorials Point India Private Limited
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We are going to cover a very important
topic that is testing levels.

So, testing itself may be defined at
various levels of SDLC.

It is not like that, that at the end of
the development process, then only the

testing phase will be beginning.

At the different SDLC phases, we can go for
the respective testing which is applicable.

So, it is better to go the development and
the testing process simultaneously.

So, the testing process runs parallel to
the software development and before

jumping to the next
stage, its stage should be

tested and validated
and respectively verified.

And if you find that
yes, everything is okay,

then you shall go for the next phase
of the SDLC.

So, testing separately is done just to
make sure that

there are no hidden
bugs and issues left in the software.

So, software is tested on various levels.

So, here we are having the list of these
levels.

So, unit testing, integration testing,
system testing.

System testing is having
functionality testing,

performance
testing, security and portability testing.

We are having the acceptance testing.

That is, we are having two variations
here.

One is the
alpha testing, another one is the beta

testing and then
we are having the regression testing.

So, let me discuss all of them in this
particular sequence.

So, at first we are going for the unit
testing.

So, what is unit testing?

While coding,
the programmer performs some tests on

that unit of
program to know if it is error free or not.

And testing is performed under white box
testing approach.

We know that in case of white box testing
approach, the tester is having the access

over the codes and
mostly in this cases, the

developer
is to carry out such testing programs.

So, in this case, if
we find that there is some

errors are there, the
test results are not okay.

In that case, we can change the code,
we can access the code accordingly.

Unit testing helps developers decide that
individual units of the program are

working as per requirement and they are
error free.

So, that is the purpose of the unit
testing.

So, here we will be selecting each and
every module or the unit of the program.

And then we shall go on or carry on
testing on each one of them to check

whether they are independently working
well, error free or not.

So, in case of unit testing, what will
happen?

Here we are having the list of test cases
and this is the module to be tested.

So, this test cases, on this test cases,
this module will

be executing and
what are the features we are going to test?

That is the interface, the local data
structure which has been used in the

module, the boundary conditions and then
independent paths and error handling paths.

So, all these things will get tested in
the unit testing which will be carried out

in the most of the cases by the
developers.

Next one is our integration testing.

So, even if the units of softwares are
working fine individually, there is a need

to find out
if the units if integrated

together would also
work without errors or not.

We are having multiple units are there,
they are individually tested.

Now, we are finding that yes, all these
units are working fine, but if they go on

integrating, if they go on integrating to
develop a certain subsystem or the system,

in that case, are they working jointly?

Are they cooperating each other?

Is there any errors are occurring there or
not?

So, that will be tested in our integration
testing.

So, from the very name integration,
you are getting this idea.

So, now, there is a
need to find out if the units if

integrated together would also work
without errors.

For example, argument passing and data
updations etcetera should be tested.

So, from one unit I am calling another
unit, I am passing some arguments,

whether those arguments
are properly getting

interpreted by the receiving units or
not.

So, all these things, all these issues
will be tested in our integration testing.

Next one, we are going for the system
testing.

The software is compiled as product and
then it is tested as a whole.

So, this can be accomplished using one or
more of the following tests.

So, here we are not going for unit device
testing, not going for integration

testing, but here we are going for the
system testing.

Now, When the
software has been compiled, now it is

running, now
the test cases are to be applied on them.

So, first one under this system testing,
we are having this functionality testing.

So, tests all functionalities of the
software against the recommend list.

So, there is a functionality testing.

Next one is a performance testing.

This test proves how efficient the
software is.

It tests the
effectiveness and the average time taken

by the software
to do the required or the desired task.

So, in
case of performance testing, it is not

enough whether the
task is getting executed or not.

That is not enough, but also we want to
check that how much time it is taking to

perform a certain task.

Performance testing is done by means of
load testing and trace testing,

where the software is put under high
user and high

data load
under various environment conditions.

So, it is not only to test whether one
user can access the software and what is

the performance, what is the accessing
time.

That is not the main thing.

Also, we are going for this load testing
when the software is supposed to deal with

huge amount of data,
trace testing, where

multiple users will
be working on the software.

At the same time, say millions of users are
working on the software at the same time.

Now, at that moment, is the software
working fine?

Is the software giving the response within
the expected duration of time?

So, all these things will be done in the
performance testing.

Next one is the security and portability.

This tests are done when the software is
meant to work on various platforms and

accessed by number of persons at the same
time.

So, that is the security and the
portability.

But the software will be working on the
different platforms.

Next one is our acceptance testing.

So, when the software is ready to hand
over to the customer, it has to go through

last phase of testing
where it is tested for

user interaction and
the respective response.

So, this is important because even if the
software matches all user recommends,

if the user does not
like the way it appears

or works, then obviously
it may get rejected.

So, this acceptance
testing is actually checking whether

the software would be getting accepted by
the user or not.

The software is working fine.

The performance is ok.

The desired results are coming.

But the way in which it works or the
appearance of the software, if the client,

if the user, if they do
not like that one, the

software may get rejected at the final
stage.

So, here we are considering two types of
testing.

One is the alpha testing, another one is
beta testing.

The team of developer themselves perform
alpha testing by

using the system as
if it is being used in work environment.

So, now we shall make one environment
within the developer's site.

So, we shall check that if this particular
software is being used in the work

environment, then what is the feedback?

They try to find out how users would react
to some actions in the software and how

the system should respond to the
respective inputs.

So, they are making one environment,
some working environment where this

particular software will be tested by the
respective users.

But remember this
one in case of alpha testing,

the testing will be done
at the developer's site.

So, that is
very important and that is causing the

difference between this alpha testing
and beta testing.

In case of beta testing, after the user is
tested internally, it is handed over to

the user to use it under their production
environment.

And only for the testing
purpose, not for the

real life use but for
the testing purpose.

This is not as yet the delivered product.

So, developers expect that user at this
stage will bring minute problems which

were skipped to attend.

So, now here this testing will be done at
the customer's site, at the user's site.

So, there this particular software will be
given for their respective testing purpose

only and they will be using this one in
the production environment.

And what about the feedbacks we are going
to get?

So, that will be analyzed and accordingly
the actions will be taken.

We are having this regression testing.

So, whenever a software product is updated
with some new code, features or

functionalities, it is tested thoroughly
to detect if there is any negative impact

on of the added code and this is known as
regression testing.

So, whenever
we add some new code, whenever we

are adding some new
features or functionality,

whether the software is working fine,
it is getting accepted by the users or not.

So, that is the testing
whatever you are going

to do is known as the
regression testing.

Now, let us go for this particular diagram
which I have made for you.

And in this diagram, I am trying to show
you that testing

activities can
have this sort of different categories.

For each one of them, I have gone for the
respective subcategories.

So, you can remember this picture.

If you can remember this one, then if you
can produce this one in your exam copy,

then obviously that will be good enough
for you.

So, in this way, we have discussed in this
video that what are the different testing

levels that are possible and when to apply
which one.

Thanks for watching this video.

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