Difference Between SDLC and STLC

Difference Between SDLC and STLC: SDLC and STLC are both acronyms of software development life cycle and software testing life cycle. The difference between SDLC and STLC lies in the use of these two models for different purposes.

SDLC is mainly used to define steps that are going to be taken while developing a software application from start till the end of its lifecycle, whereas STLC, mainly used to define the steps that are going to be taken while testing a software application from start till the end of its lifecycle.

Software Development Life Cycle (SDLC)

It is based on the Waterfall model. Software Life Cycle (SDLC) is a series of methodical steps that takes an application from being just an idea to a fully functional software program, ready for use by its intended users. The SDLC consists of five main phases:

This process may take some time to execute and when finished, we have a new application that is ready to be used by the targeted end-users.

Software Testing Life Cycle (STLC)

It defines the series of steps taking place during the testing of applications, whether it’s in the development phase or maintenance phase. STLC can be defined at a much higher level. Several life cycles can be identified. These commonly used software testing life cycle levels are unit testing, system testing, integration testing, and acceptance testing.

There is also a whole process that is defined with the implementation of SDLC and STLC known as Software Development Lifecycle Management (SDLM). In SDLM project managers define the development phases in an organized manner by considering all risks and resources required for the completion of the project.

Difference Between SDLC and STLC

Now after getting a basic knowledge of SDLC and STLC, let’s try to find out what are the major difference between SDLC and STLC .

SDLC and STLC is mainly differentiated on following factors

Software Development Life Cycle (SDLC)

  • It is mainly used to define steps that are going to be taken while developing a software application from start till the end of its lifecycle.
  • It is mainly used in the context of Waterfall Model only.
  • It is a very formal model and mostly proprietary in nature.
  • It is purely used for a development purpose in the context of the Waterfall model only.
  • It is not used for testing purpose.
  • It is not used for project management purpose.
  • Each step in this process has a fixed time duration.
  • It is used mainly for the maintenance and enhancement of software applications.
  • All activities are documented in a project plan.
  • The following diagram depicts the steps involved in software development life cycle.
  • It is a very important process to follow while developing software applications.
  • It is not very flexible.

Software Testing Life Cycle (STLC)

  • It defines the series of steps taking place during testing of applications, either it’s in development phase or maintenance phase.
  • STLC can be defined at a much higher level.
  • Several life cycles can be identified. These commonly used software testing life cycle levels are: unit testing, system testing, integration testing, and acceptance testing.
  • STLC is used for maintenance of software applications in addition to development.
  • Activities are documented in a test plan.
  • The following diagram depicts the steps involved in software testing life cycle.
  • It is a very important process to follow while testing software applications.
  • It is not very flexible.
  • It is not used for development purpose.
  • A formal model is not defined.
  • It is mainly used for a testing purpose in the context of Waterfall Model or V-Model only.
  • It is used for management purpose in addition to testing too.
  • All activities are not documented in a plan.
  • The following diagram depicts the steps involved in software testing life cycle.
  • It is a very important process to follow while testing software applications.

Software Development Lifecycle Management (SDLM):

It is a management process that defines steps for managing software development projects from start till the end of their lifecycle.

SDLM Process:

In SDLC, you define what type of application you want to develop and which technology you’ll use. In the next step, you’ll allocate resources for selecting team members. Now it’s time to start with the software design and development.

After completion of development, it is time to test, deploy and maintain your application. SDLC can be implemented in Waterfall Model only.

Keypoints on SDLM:

  • It is comprised of different steps.
  • Activities are documented in a project plan and test plan.
  • It is a formal model.
  • It is used for both development and testing purpose.
  • It is mainly focused on Waterfall Model or V-Model.
  • It is used for software development in addition to testing too.
  • It is also used for project management purpose.
  • It is more flexible.
  • All activities are documented in a project plan and test plan.

Software Testing Life Cycle Management (STLM):

It is a management process that defines steps for managing software testing projects from start till the end of their lifecycle.

STLM Process:

In STLC, you define what type of application you want to test and which technology you’ll use. In the next step, you’ll allocate resources for selecting team members to execute tests based on requirements and objectives. Now it’s time to start with the test development in order to find bugs and defects in your software application. After completion of testing, it is time to fix bugs and deploy and maintain the application.

Keypoints on STLM:

  • It is comprised of different steps.
  • Activities are documented in a test plan.
  • It is more formal than SDLC.
  • It is used for both Development and Testing purpose.
  • It focuses on Waterfall Model or V-Model only.
  • It is mainly used for software testing purpose too.
  • It is also used for project management purpose.
  • It is flexible.
  • All activities are documented in a test plan.

Conclusion on SDLC and STLC

Each model has its own advantages and disadvantages. It is up to you to determine which one will suit your needs the most. When you develop a software application, it is very important to use SDLC. While testing, it’s better to use STLC due to its flexibility and changeability. It’s more suitable for testing purposes.

Please let me know how you like this post in the comments section below. If you have any questions, feel free to ask them too and I will try my best to answer them as soon as possible. Thank you very much for reading!

I love open-source technologies and am very passionate about software development. I like to share my knowledge with others, especially on technology that's why I have given all the examples as simple as possible to understand for beginners. All the code posted on my blog is developed, compiled, and tested in my development environment. If you find any mistakes or bugs, Please drop an email to softwaretestingo.com@gmail.com, or You can join me on Linkedin.

Leave a Comment