Software testing is an integral part of SDLC (Software Development Life Cycle). It is vast and integral process that determines the capability of software. But before getting into it, it will be helpful to discuss something relevant as an overview of the process in question.


Software is a computer program, or a set of commands for the computer. The computer performs a task or the other when these commands are executed. In fact, software is the intangible component of the computer system. All computer programs, including various applications, executable files (.exe) and libraries, etc. belong to this category.

As such, software entities interact with various hardware components of a machine, as a result of which computation is performed. Hardware and software ideally complement each other and as such, one cannot perform its task without that of another.

software testing

Why software testing

Software that is developed may contain certain errors, other than those in the codes. Some of the common software problems include

  • Faulty calculation (say, division by zero)
  • Incorrect and ineffective data edits
  • Erroneous matching and merging of data
  • Faulty processing of data relationships
  • Data searches that provide incorrect results and
  • Incorrect file handling, etc.

As such, each one of these factors are sufficient to provide incorrect and insufficient support to business requirements. To avoid this mismatch between what is expected from software and what it computes up; the process of software testing proves to be an effective procedure.

What is software testing?

Taking the cue from above, software testing can be described as an investigative procedure to ascertain the quality and the performance-level of software. It assists the stakeholders understanding the risks involved in implementing the software.


Objectives of software testing can be listed down as follows.

  • To ensure, the software in question is capable to meet the requirement standards
  • To locate and debug errors
  • Validating every line of the existing code
  • To study and understand the scope of functionality of the software and
  • Dry run the software with probable test cases, etc.

Ideally, a software testing should not be too simple, neither too complex. A successful example of software testing is the one that locates a yet undiscovered error.

Software verification and validation

Software verification involves the process to review and evaluate documents, client specifications and action plan, etc. Common tools to perform this step include

  • Checklists
  • Interactive meetings
  • Conducting tech run, etc.

Validation is the actual testing process for software and is performed after verification course gets over. The two processes are conducted in cyclic order till software becomes error-free.

Common testing procedure

Top-down and Bottom-up are two common testing procedures for software.

  • In bottom-up approach, as the name suggests, testing is initiated on the components at the lowest level. The program modules, functions and procedures residing at the base of the system are tested first and gradually integrated with those of the components at the higher levels, which are then tested for locating bugs and functionality errors.
  • In top-down approach, on the other hand, top-most components are tested first and then gradually, the components lower down the order are tested.

As such, there are even automated simulators that have been designed to facilitate automated testing of software.

Developing integrated software for commercial purpose often tallies to millions and billions of dollars. Therefore, aspect of software testing is crucial to the development process.