Understanding of the software testing levels
                     The Four Common Software Testing Levels that Everyone Needs to Know
Software  Testing  plays  a  major  role  in  the  successful  software  implementation  process.  Many
enterprise projects are failed because it is not meet the objectives that lead to major effects on the
CRM, Accounting, ERP of the organizations. Software Testing to be done whether manually or with
some automation tools such as Appium, Selenium, API, ETL, Load Runner, QTP, and JMeter to point
out the errors and defects which are made during the development process  and to debug them
before deployment.
Few benefits of implementing the Software Testing
The implementation of software testing brings the following advantages to the organization for the
proper software development workflow:
 It ensures that the declared functions and specifications have been implemented properly
 It assures the quality of the final project/product
 It makes sure the codes have no errors
 It validates the project is easy to use and does not mislead the user
 It confirms the adaptability and operability of the application that can run anywhere
Different Levels of Software Testing
There are four levels of software testing such as Unit Testing, Integration Testing, System Testing, and
Acceptance Testing which can be done in any project or application to ensure its quality that falls
under  two fundamental  methods such as Black  Box Testing and White  Box Testing.  In  Block  Box
Testing, the internal structure or design or implementation of the application is not known to the
testers  whereas,  in  White Box Testing,  the internal  design or structure or implementation of  the
application is known to the tester. 
Unit Testing
Unit Testing also is known as Component Testing focuses on to verify the functional correctness of
standalone modules. The application segregated into the smallest testable parts to perform the test
methods and show every individual component are perfect and fulfill the requirements as per the
expected  functionalities.  There  are  some frameworks  to  automate  the  testing  task  that  vary  for
programming languages. 
 NUnit is the framework written in C# to support all .Net applications. 
 JUnit and TestNG for Java, 
 Embunit for C, C++, and 
 Html Unit for JavaScript. 
Unit Testing will be performed at the first or early stage of developing the software to minimize the
development risk. 
Integration Testing
Integration Testing is done after the Unit Testing by combining two or more unit tested modules to
implement the integration test that verifies the integrated modules are working fine as expected. It
focuses  on  exposing  the  faults  during  the  interaction  of  integrating  units  of  the  application.
Integration Testing can be done with four types such as Big-Bang, Bottom-Up, Top-Down, and Mixed
Integration Testing. 
 Big-Bang Approach  implies the testing of all the modules of the application put together and
tested in one shot. It can give positive results only for a small application. If any bugs found in
integrated testing, it is difficult to localize and cost more for fixing them.
 The Bottom-Up Approach involves the testing process of lower-level modules with the higher-
level  modules  until  all  the  modules  are  tested  using  some  test  drivers  which  means  the
temporary replacement of the actual modules.
 Top-Down Approach means that the integration testing will be done from higher-level modules
to lower-level modules and finally integrated with the lower level modules to the higher-level
modules to verify the whole application is working fine.
 Mixed  Integration  Testing  incorporates  the  combination  of  both  bottom-up  and  top-down
integration approach. This is also known as sandwiched integration testing that overcomes all
the shortcomings of both approaches.
System Testing
System Testing involves the process of testing the entire components of the application or software to
ensure the overall product or product meets the expected requirements. It focuses on the validation
of  end-to-end  system  specifications.  It  is  performed  with  the  major  steps  such  as  testing  the
environment setup, creating test cases, creating the test data, executing the test cases, defecting the
reports, testing the regressions, defecting the logs, and finally retest the whole application. There are
four types of System Testing can be done as follows:
 Performance  Testing: It  carries  out  the  testing  of  system  speed,  scalability,  reliability,  and
stability of the software application
 Load  Testing:  It  carries  out  the  determining  of  the  behavior  of  the  application  on  input
overloads.
 Stress Testing: It carries out to check the robust and strength of the application with the various
loads
 Scalability Testing:  It carries out to test the performance and capability of the application to
scale up or scale down as per the number of user requests.
Acceptance Testing
Acceptance Testing is involved in the testing of the application or product has given the green light or
not. It focuses on ensuring the quality of the product that all the requirements are meet out and
ready for deployment.  Acceptance Testing will  be done with the steps such as planning the test,
design the test cases, choosing the testers, executing the test cases, documenting the test cases,
fixing the bugs, and prepare for the product launch. This acceptance testing is used to detect the
defects, find out the quality of the developed product, whether the product meets the user needs,
eliminates the issues raised when deploying. Types of Acceptance Testing are as follows:
 User Acceptance Test: To determine the product is working correctly for the user.
 Business Acceptance Test: To determine the product meets the business goals and purposes
 Contract Acceptance Test: To determine the contract terms are fulfilled as per the Service Level
Agreement (SLA) to ensure the payment only after the quality product delivered.
 Regulations Acceptance Testing: To determine the product violates any rules and regulations of
the government where the product is launched.
 Operational Acceptance Testing: To determine the testing of recovery, compatibility, reliability,
and maintainability of the product that ensures the readiness.
 Alpha Testing: This testing will be done by the specialized testers in the development process
itself which is optional for the application.
 Beta Testing: It is the level of testing that is verified by the end-user who asses the product
before deployment and give feedback if  any bugs to be fixed or enhancing the product with
much more improvements.
Conclusion
Software Testing is done to ensure the quality product before the deployment. It is done with the
above methods for small and large applications according to its requirements. If the product comes
back to the development process after its delivery, it interrupts other project workflows for sure.
Therewith, Testing is always worth the effort to avoid unnecessary issues after the delivery of the
product. It has a wide range of opportunities for certified and skilled testing professionals for global
companies. Learn the Software Testing Training in Chennai with the required tools and testing at SLA
Jobs and discover the great opportunities ahead of you in the IT industry.