STLC and SDLC: main differences and how to apply them to software development

When we talk about high-quality software development, we need to keep in mind the need to implement certain extremely well-structured methodologies so that all the gears work in harmony. Two, in particular, are gaining ground and becoming increasingly important: Software Development Life Cycle (SDLC) and Software Testing Life Cycle (STLC).

Despite the fact that they’re connected and have the same purpose – to deliver reliable software – they focus on different angles of the development lifecycle. While SDLC covers the entire software creation process, from the initial concept to the deployment and maintenance of the product, STLC focuses on the testing stages, ensuring that the product meets quality standards before its release.

Next, we’ll explore each of these methodologies, understand their pros and cons, and how they work together to speed up software development and guarantee high-quality deliverables.

SDLC (Software Development Life Cycle)

SDLC is a framework that describes the distinct phases involved in developing high-quality software applications. It’s an approach that ensures product resources are used efficiently, that the project is completed, and that software is created that meets the user’s business needs.

SDLC includes a series of phases that are connected and, when well configured, guarantee the success of the project. These phases are iterative, which means that they can be repeated or adjusted whenever the team considers it to be necessary, guaranteeing continuous improvement and adaptability throughout the development process.

Phases of SDLC

SDLC consists of the following phases:

• Planning
  This phase involves defining the scope of the project, identifying requirements and setting goals for the software development project.
  
  
• Analysing
  This phase focuses on understanding user needs and translating them into functional requirements for the software.
  
  
• Design
  This phase involves creating the architectural design for the software, defining the system components and specifying their interactions.
  
  
• Development
  This phase involves writing the actual code for the software based on the approved design.
  
  
• Testing
  This phase involves rigorously testing the software to ensure that it meets functional and non-functional requirements.
  
  
• Deployment
  This phase involves releasing the software into production, making it accessible to users.
  
  
• Maintenance
  This phase involves ongoing support, bug fixing and improvements to the software to ensure functionality and user satisfaction.

STLC (Software Testing Life Cycle)

STLC is a structured process that focuses on the actions surrounding the software testing cycle in order to guarantee its quality and functionality. It provides a framework for planning, executing and documenting all the testing stages, making the testing stage efficient enough to guarantee the success of the product.

STLC is directly integrated into SDLC, acting as a decisive point in the development process. As we know, tests, when well-defined and applied, are fundamental to ensure that the software meets user expectations and works correctly in real scenarios. With this, STLC aims to identify flaws early in the development process, minimising the cost and time needed to correct them.

Phases of STLC

STLC usually consists of the following phases:

• Requirements analysis
  This phase involves understanding the requirements for the software and identifying testable conditions.
  
  
• Test planning
  This phase involves creating a detailed test plan, outlining the test objectives, test cases and overall test strategy.
  
  
• Test design
  This phase involves developing specific test cases and scenarios to cover the identified test requirements.
  
  
• Setting up the test environment
  This phase involves configuring and setting up the test environment where the software will be tested, ensuring that it mimics the real-world production environment.
  
  
• Test execution
  This phase involves executing the test cases and recording the results.
  
  
• Defect reporting
  This phase involves documenting any flaws or bugs found during testing and reporting them to the development team for resolution.
  
  
• Test closure
  This phase involves summarising the testing activities, analysing the results and creating reports to document the overall testing process.

Differences between SDLC and STLC

The importance of integrating SDLC and STLC

Integrating SDLC and STLC is fundamental to ensuring product success. When these two cycles work in perfect harmony, they guarantee quality, efficiency and continuous improvement, leading to reliable products.

By integrating SDLC and STLC, the following points can be assured:

• Identify and resolve defects early in the development process, minimising the cost and effort required to correct them later.
• Improve communication and collaboration between the development and testing teams, ensuring that everyone is aligned with the project’s goals.
• Reduce the risk of software failures by increasing the software’s reliability and stability.
• Ensure that the software meets user expectations and business objectives, leading to increased user satisfaction and commercial value.

Conclusion

SDLC and STLC are essential methodologies for the software development and testing stages. Understanding these methodologies on a deeper level and integrating them efficiently is critical for companies looking to develop high-quality software.

By adopting systematic approaches to the development and testing phases, companies can create robust software that fulfils users' needs.