Quality software development requires a clear methodology for getting from idea to final product. The software development lifecycle (SDLC) is a 7-step framework that businesses can use to help achieve software development goals.
This article lists the 7 SDLC stages and goes into detail about each. They are:
- Requirements and analysis
- Project planning
- Design
- Coding and implementation
- Testing
- Deployment
- Maintenance
What is the Software Development Lifecycle (SDLC)?
SDLC is a standardized process that software development teams and companies use to build and test software products. It’s a step-by-step development process that aims to create high-quality software efficiently. A project following the software development lifecycle may be focused on building a new software product or on improving an existing one.
The traditional 7-stage software development lifecycle has inspired other modern software methodologies like Agile and DevOps.
What are the 7 Software Development Lifecycle Stages?
Stage 1: Requirements and analysis
In this step, you build the foundation for the rest of the phases of SDLC by gathering requirements from clients and stakeholders. You typically discuss the goals and desired results of the software development project as well as end user requirements.
It’s valuable to document the requirements of the project along with the existing pain points that developers should strive to eliminate with the new software. This documentation will be shared with developers to help them in the next SDLC stage.
Stage 2: Project planning
In this phase, senior development team members take the information gathered in stage 1 and use it to plan the software development project. Discussion revolves around items like:
- The scope of the project
- The project timeline
- Anticipated obstacles
- Opportunities and risks
- Estimated costs
Again, these elements should be documented for use in future SDLC stages. Make sure you have a clear plan before you proceed—this step will keep your project focused and on track.
Stage 3: Design
After gathering requirements and planning your project, you’re ready to elaborate your plan into a software design. This is commonly documented in a Design Document Specification (DDS). The DDS may include specification such as:
- System overview
- Platform(s)
- Programming language
- Dependencies
- Planned security measures
- Goals and guidelines
- Constraints
This information, along with the project plan from stage 2, will be essential to developers in the coding and implementation stage. It’s important to make sure that stakeholders are on board with the design before continuing to the next phase of the SDLC.
Stage 4: Coding and implementation
You’re finally ready to take your requirements, plan, and design and translate it into software. Following the design and project plan helps your development process stay efficient.
In this phase, developers code in the chosen programming language. Specialized tools may be required, such as compilers, interpreters, and debuggers.
This stage usually takes the longest of all the SDLC phases.
Stage 5: Testing
Stage 5 involves the QA team testing the software for errors and deficiencies.
Testers look at criteria like:
- Does the software produce the desired results?
- Are the requirements and objectives (outlined in the first two steps) met?
- Are there any errors or bugs in the software?
Testing can be manual or automated. While the SDLC model lists testing as separate from coding and implementation, it’s best to start the QA process as early in the software development lifecycle as possible.
Stage 6: Deployment
In this stage, your final software product is delivered to the customer. This process is commonly automated, but it’s still important for your team to keep a close eye on the deployment. You might choose to start with a small segment of customers before deploying the software globally.
At the end of this stage, the product is ready for end users.
Stage 7: Maintenance
Just because the new software has been rolled out to customers doesn’t mean the development team’s work is done. In phase 7 of the software development lifecycle, you continue to update the software to eliminate bugs or add more required features. The changes and updates could be based on customer feedback, unexpected issues that arise, or the evolving requirements of the business.
Software maintenance could be a quick fix or it could send you back to the beginning of the SDLC.
As mentioned in the previous step, the development team may choose to first release the product to a smaller population of customers before implementing a wider release. This can mitigate the need for maintenance and offer insight into how the product is performing so that developers can make any last adjustments prior to its final release.
The importance of the SDLC
Implementing a defined software development process improves the quality and efficiency of your software project. While the exact steps of the software development life cycle vary by project, company, and industry, the SDLC is a solid foundation for planning, designing, developing, testing, and maintaining software.
