Software Development Lifecycle: The SDLC Stages and Process

By Joshua Gross, 21 January, 2023

Developing software can be a drawn-out and tedious process, particularly if you aren't organized right from the start. When you dive right into the development phase without a bomb-proof plan, you're basically asking for delays, budget issues, and costly mistakes.

Using a project management model known as a software development lifecycle can help teams improve consistency, efficiency, and overall quality when creating a new product.

An SDLC consists of a number of phases that will need to be passed through to create a product suitable for deployment into the market. Depending on your business goals and the nature of the project, the number and nature of the phases can vary a bit. In this article, we'll look at one of the most common SDLC models to help you design a custom plan that suits your goals and needs.

What Is a Software Development Life Cycle?

The bird's-eye view breakdown of all the stages involved in creating software is known as a software development lifecycle. In order to build an interactive, predictable framework, SDLCs are custom designed in order to guide teams through the primary development stages.

The precise number of phases and the character of each of these steps can vary depending on the business and the project in question. For this reason, you'll find different outlines describing the stages of an SDLC when researching the topic.

Custom designing an SDLC can help businesses create a solid foundation that they can use every time they create a software-related project. It allows teams to work faster and with more consistency while also allowing companies to maximize their ROI. This is possible because an SDLC helps businesses:

  • Keep projects within the assigned budget
  • Meet deadlines consistently
  • Correctly prioritize their tasks
  • Keep product features aligned with business goals
  • Reduce vulnerabilities and bugs during production
  • Reduce the number of post-launch fixes that affect user experience
  • Reduce the occurrence of team members spending time on conflicting, redundant, or low-value tasks

Though SDLC strategies were first introduced in the 1960s, the ideas and primary concepts have undergone quite an evolution over time. Perhaps the most impactful of these changes have affected the testing phase of the process. Testing is often considered a traditional SDLC stage, but some modern companies integrate these activities throughout the entire life cycle to ensure a secure product.

Software Development Lifecycles: The Process

Each stage of software development is outlined in an SDLC. Each phase has its own goals, tasks, instructions, expectations, deliverables, documentation, and personnel.

Depending on the business and its specific goals for the software project, the exact character and number of the steps can vary. The average project will commonly have between five and seven phases, while a large and complicated process might require ten or more major stages.

An output results from each stage of the process, such as a diagram, document, working software, or other product. In order to move on to the next step in the process, the respective output must have been produced from the previous step.

That being said, not all SDLC strategies are 100% linear– it isn't uncommon for teams to take a few steps back to make improvements or fix problems when necessary.

It's essential that the software development lifecycle of a project is regularly reviewed and even updated. A number of players participate in this process, including developers, business analysts, stakeholders, and QA team members.

The SDLC Stages

There are similar steps to every software development lifecycle, but it's important for businesses or individuals to custom-build SDLCs that fit their goals and particular project.

Let's take a look at the most common model for SDLCs.

1. Requirement Analysis

This part of the project is the foundation for the entire product. A collective effort is required to complete this stage thoroughly, including participation from leadership, business analytics, development, operations, and security teams.

There are a number of critical questions that will need to be answered in this initial stage, including:

  • What is the project's goal?
  • What is the business hoping to achieve with the final product?
  • What are the hard deadlines we need to be concerned with?
  • Is this an existing system upgrade, or does brand-new code need to be written?
  • Can we take care of this in-house, or will we need to outsource either a portion of the project or the entire project?

Setting realistic goals, creating a comprehensive schedule, and creating a reasonable budget are all essential steps in avoiding one of the most frustrating potentials of any software product– a stalled project.

The output from the requirement analysis step is a Software Requirement Specification (SRS) document. This includes all of the specifications for the project, including security, hardware, software, and network specifications. Additionally, the file will include cost estimation, project scheduling, capacity planning, resource allocation, and provisioning. Essentially, the project goals and scope will be defined in the SRS, as well as rough project estimates and the project requirements.

If you're looking for a breakdown of the steps involved in planning a software development project, check out this guide.

2. Feasibility Study

The second step is the feasibility study, which aims to evaluate whether the business goals and resources are compatible with what was discovered during the requirements analysis. The feasibility study is performed by senior business analysts, who typically focus on the following factors:

  • Legal implications
  • Budget limitations
  • Availability of in-house skills
  • Operational requirements
  • Required project timeline

What is discovered during this process will then be added to the SRS document that resulted from step one. Upper management or approved decision makers will then review the report in order to approve the project schedules, the project plan and direction, the estimated costs, and the resources that will be required.

If the higher-ups aren't ready to sign off on the document, they can ask the team to take a step back and review specific aspects of the project defined in the requirements analysis. When this step is complete, there is a new and improved version of the SRS document that the proper leadership team has given the go-ahead.

3. Design

The team is free to start creating a design plan for the product once the project direction has been approved. This phase includes designing all of the primary aspects of the software product, including its:

  • Infrastructure requirements
  • Architecture (databases, programming language, operating system, interfaces, APIs, pre-made templates, and so on)
  • User interface design
  • Security measures (password protection, SSL encryption, etc.)

All of this information will then be collected in the Design Document Specification (DDS). It is then passed off to a stakeholder that analyzes the risk, product robustness, design modularity, and time constraints. If they are satisfied with what they find, they can then approve the direction of the project.

It is during the design phase that some companies choose to build a prototype of their product. While the time-consuming nature of prototype development can turn some people off to this optional step, it can end up saving a lot of time and money in the long run. By creating a prototype, you can avoid the need to make extensive changes once the development phase has been completed.

4. Coding

Finally, it's time for the development team to use the DDS in order to start writing the code for the software product. In many circumstances, the coding and software development phase is the most time-consuming step in the process.

The output of this phase is well worth the wait, however– operational software that fulfills all of the requirements that were outlined in the SRS and DDS. Though advanced testing is still needed, basic tests such as code reviews for different device types and static code analysis are involved in the coding stage.

Are you outsourcing the software development aspect of your project to freelancers? Make sure you check out these twelve online coding interview tools that will help you select the most qualified candidates.

5. Testing

Now that you have a fully functional piece of software, it's time to perform in-depth and extensive testing. Many different methods can be used to evaluate the software from every angle. These include:

  • Performance testing
  • Security testing
  • Acceptance testing
  • Integration testing
  • Code quality testing
  • Unit testing

This phase can be sped up by using automated tests. That being said, a number of tests, such as penetration tests, still benefit from manual execution.

If flaws are found in the software product, the developers will go back to the coding phase until they have created a stable and up-to-quality product free of bugs or defects.

Once the testing phase is over, the software product should have been thoroughly tested, and any issues that were discovered should now be resolved.

6. Deployment

Now that the product has gone through extensive testing and all problems found during the process have been solved, the product is ready to be deployed in the production environment. In some cases, a company might create a replica of the product environment to perform user acceptance testing (UAT).

These days, many companies will choose to deploy their new product to only 10-15% of users at first before gradually increasing the availability to the rest of the customer base. This can help ensure that there aren't any UX issues before it is available to a wider audience and gives some time to address issues if they are discovered.

7. Maintenance

Periodic reviews and updates are necessary for any software product. Inevitably, there will be user feedback about the experience of using the software that requires that changes are made. This might include adding new features, fixing bugs, or upgrading to a newer version.

When new problems are discovered with the software, the team can revisit whatever stages of the SDLC are necessary to rectify the situation. It's common for bugs and issues to bring the team back to the coding stage, while major flaws might mean returning to the design stage.

Software Development Lifecycle Best Practices

When you are considering utilizing the software development lifecycle model for your next project, there are a number of best practices you will want to keep in mind.

These best practices include:

  • Taking advantage of automated tests
  • Focusing on security from the start
  • Always keeping documentation accurate and up-to-date
  • Staying up to date on the latest security threats
  • Maintaining excellent data hygiene
  • Creating a standardized code review process
  • Creating learning opportunities for your team to learn about best practices through in-house workshops

The Benefits of SDLC

Implementing a custom SDLC for your next project can tremendously impact your ability to stay within budget and on time, all while never compromising on quality.

Let's look at a full list of the benefits of using a software development lifecycle model.

  • Reduces the likelihood of successful cyber attacks
  • Reduces development costs
  • Allows for an improved UX
  • Improves the quality of the final product
  • Reduces the likelihood of project failure
  • Allows for more precise budget estimations, project planning, and scheduling
  • Faster time to market
  • Allows for a deeper understanding of the needs of both the customer and the business
  • Improves the quality of documentation
  • Allows for more opportunities for stakeholders to offer feedback during the project
  • Allows for improved communication
  • Offers the opportunity to learn about your team's abilities and potential room for improvement
  • Allows you to create a backup and disaster recovery (BDR) plan that suits your needs

All that being said, this doesn't mean that using an SDLC is a completely foolproof system. After all, humans are still involved in the process, and problems like poor cross-team communication and rushing into the development stage can still occur if teams aren't sticking strictly to the plan they've outlined.

For this reason, it's important to partner with a software development team that has a time-tested system for producing high-quality, bug-free software efficiently.

Searching For the Right Software Development Team?

Choosing the right software development team to work with is essential to building a successful product. Not only can you trust that the final product will be up to your quality standards and in line with your expectations, but you also can rely on an experienced and knowledgeable team to utilize models and methodologies that ensure the project will be created in the most efficient manner possible.

At Planetary, we love to help businesses of all sizes create custom digital products that help them achieve their goals. Whether you're a tiny startup or a multinational corporation, feel free to contact us and tell us about your project.