SDLC: 6 Main Stages of the Software Product Development Lifecycle

Software development isn’t a simple process, and it requires a systematic approach. To build a successful application, it’s essential to follow the stages of the software product development lifecycle. They aim to make the process of building an app as effective and flawless as possible.

When googling stages of the software development lifecycle (SDLC), you’ll find that different sources give different information. While the particular SDLC stages may vary slightly from one vendor to another, their goal is to ensure a consistent development process.

In this article, we answer the question: What are the stages of software development? We’ll go through each stage and briefly describe its essence so you have a clear understanding of what to expect from the entire process of creating an app.

Why is the SDLC important for successful software development?

Before we start discussing the software development lifecycle phases in detail, let’s see why following them is important.

Stages of the SDLC ensure a transparent software development process. When stages are well-defined, it’s much easier to manage the development and make sure it aligns with the project schedule, business goals, and project requirements. Here are key advantages of following SDLC phases:

• Effective team communication. Every team member understands their roles and responsibilities, and as a result, the risk of misunderstanding, rework, and missed deadlines is reduced.
• Efficient resource management. When the development plan is well-defined, it’s easy to rationally allocate resources such as time, budget, and human effort.
• Risk management. As a delivery team analyzes possible risks before development, it’s possible to effectively address issues that come up through the process and therefore significantly reduce their impact on the project’s schedule and cost.
• Precise requirements for each development stage. All team members involved in the project know from the beginning the requirements for all stages of the software development process and the desired outcome. This makes it easy to monitor progress, evaluate results, and achieve success.

6 stages of the SDLC

The six main stages of the software development lifecycle are planning, requirements elicitation, application design, development and testing, deployment, and maintenance.

Let’s consider each stage in detail.

1. Planning

The software product development lifecycle has to start with proper planning.

While some business owners believe they can rely on their promising ideas combined with the experience of software engineers to build a superb product, it doesn’t really work that way. Why? Simply because ideas that seem good at first sight can actually be infeasible. Lack of research and planning is one of the main reasons why startups fail.

The only way to understand if the software product you want to build has real potential to succeed is to gather information, analyze it, and use the results to validate your idea and create a clear development plan. This is done during a discovery phase, which takes place at the beginning of the software development project and allows you to set the direction for the whole process.

There are several reasons why you should pay close attention to the discovery phase before moving to other stages of product development:

• It gives you a clear vision. In planning your product development, you research the niche you want to fill, your target audience, your competitors, monetization options, etc. By doing all this, you define your business needs, which are then used by your development team to bring your project to life.
• It increases the chance of creating a successful product. A single idea isn’t enough to build a new market leader. You should validate your idea and get enough proof that your idea can compete on the market before you even start looking for a software development partner and move to the following stages of the software development lifecycle.
• It saves you time. If you don’t carry out a bunch of research, you won’t know what the requirements are for the product you want to build. This will lead to misunderstandings within your team and rework. As a result, you’ll spend more time on software development and increase the time to market.
• It saves you money. Considering that you pay your development team for the time they spend developing and fixing your product, you can dramatically cut down development costs by defining your expectations from software product development at the very beginning.

So, how can you turn ideas into solid software development projects? Here are the key steps you should take:

1. Conduct market research. To understand if your idea is worth a shot, you need to know the state of the market, your competitors, and users. Gather information on what solutions similar to yours are available on the market, what value they bring, what users’ needs they can’t cover, and what users desire to see in such software. All in all, you need to understand what gaps in the market you can fill with your product.
2. Define a problem to solve, your goals, and your limitations. Your product should have a clear purpose. After market research, you will have an idea of your competitors’ weaknesses and strengths, as well as users’ pains and desires. Based on this information, define what main problems you want to solve for your users, outline the objectives and goals you want to achieve by building software, and define your project’s limitations.
3. Develop your unique selling proposition. It’s important to understand what you can offer potential customers that will catch their attention and, as a result, make them choose your solution over any other similar software. This is called a unique selling proposition — something that distinguishes your software from competitors and brings unique value to customers: i.e., solves their problems.
4. Create a plan. You should organize the deliverables of previous steps in the form of an app development business plan, a business model canvas, a project brief, and a startup product roadmap. These documents should contain your vision of the product, goals, objects, limitations, required resources, development plan, estimated timelines and budget, and other essential information needed to have a full picture of what should be done, how it should be done, and why it should be done.
5. Decide on the app architecture and tech stack. In this step, your team prioritizes app features, defines the app structure along with techniques and patterns to design and build it, and chooses the technology stack needed to bring the project to life in the most effective way.
6. Develop a proof of concept. Once you understand what you want to build, what functionality your software should have, and how you want to develop your project, it’s time to validate your idea. Creating a proof of concept (PoC) can help you with this. The main goal of the PoC is to prove that it’s technically possible to implement the product with your desired functionality, assessing the available technology stack.

As a rule, researching, planning, and building a proof of concept happens on the stakeholders’ side. But even if you only have an idea, you can start undertaking a discovery with the help of a software development consulting service and CTO as a service. A discovery team will be able to write a full business plan or carry out research in your domain and share insights that will help you create a business plan on your own.

2. Eliciting requirements

Not giving enough detail to your product development team is one of the common product roadmapping mistakes. To avoid it and ensure smooth cooperation throughout all stages of software development, it’s critical to prepare clear documentation for your developers.

After product discovery, you should have a more or less clear understanding of what app you want to build, and it’s time to communicate your idea to your development team. This involves meeting with a software development company’s business analyst (BA) and sharing your expectations during a process called software requirements elicitation. During this process, the BA works on creating an app requirements document, also known as a software requirements specification (SRS).

An SRS contains functional and non-functional requirements:

• Functional requirements describe what functionality should be available for the app’s end users.
• Non-functional requirements describe the software product’s structure, dependencies, and other technical specifications.

In addition, there are sections that describe other important aspects of software development, such as the project's objectives, types of users, and the scope of work to be completed.

Another critical step before developing software is to decide on the software development team structure. Depending on the services you need, the number of specialists will vary. There are three cooperation models you can choose from:

• In-house team. If the scope of work required to complete software product development is large, hiring a dedicated team of developers and carrying out the project within your company is one of the best solutions. In this way, you will have full control over all development phases. However, you should take into account that maintaining an in-house team leads to a higher product development cost and requires you to have experience and skills in managing a development team and put a lot of effort and time into the project, participating in all organizational processes.
• IT staff augmentation. This is a suitable solution if you already have an in-house team but lack specialists in certain areas needed to bring your project to life or simply to speed up the development process. With IT staff augmentation, you can hire external specialists to work with you on the project and not waste resources on recruiting, onboarding, and training.
• Software product development outsourcing. This cooperation model refers to hiring an external development team to work on your project. Usually, if you outsource web development services, your vendor offers you the number of specialists necessary to build high-quality software within your allocated budget and time frame. Offshoring software development is a beneficial option for projects of different scales, as you don’t need to maintain the team and can put less effort into process organization, participating only in key decision-making activities. At the same time, your project is executed by experienced specialists, as developers from outsourcing companies usually have solid expertise in product development for various industries and niches.

No matter what cooperation model you choose, it’s important to clearly communicate functional and non-functional requirements and other project details to your team. This will ensure that every team member understands their role, the scope of work, objectives, and goals at each stage of the software product development lifecycle.

3. Application design

Before starting to build your application, it’s necessary to have a layout you’ll follow. At the design stage of the product development lifecycle, your software development team will provide you with a user interface (UI) and user experience (UX) design.

The design process involves creating and prototyping all software components, showing how your software interface will look and describing how its components work together. UI/UX specialists will ensure that the product is convenient to use and provides an excellent user experience. The design is created before the actual development starts so that software engineers can develop your software in accordance with the approved design.

4. Development and testing

At this stage, the actual software product development starts. One common practice is to build a minimum viable product (MVP) first. An MVP is a small version of your software that includes a few key features or modules needed to solve a certain problem.

The point of developing an MVP first instead of a complete product is to see how the software will work in a real environment without wasting a lot of resources, including time, money, and human effort. Such an approach is not only cost- and time-effective but also can reveal issues in your product at an early stage so you can analyze and fix them before building a complete product.

Another crucial part of the process is testing, during which QA engineers make sure the product functions according to requirements. No piece of functionality can be deployed without proper testing. That’s why the testing stage is a must before making new functionality or updates available to real users. This is one of the most time-consuming stages of the SDLC, as it requires a lot of work: testing units (small pieces of source code) individually, testing their integration in one system, testing the whole system and its compliance with the software requirements specification, and checking for acceptance by end users. This process involves software usability, performance, functionality, and security testing.

Testing, as well as development, can be carried out in different ways, either in sprints after developing each piece of functionality or at the end of development when all parts of the software are ready. What option should you choose? Everything depends on your chosen software lifecycle model: Waterfall or Agile.

Waterfall model

The Waterfall approach is sequential, with each development stage isolated from others. With the Waterfall approach, development goes according to the initial plan, stage by stage, and no changes are made during the process. Thus, programming starts only when the app’s design is completely ready, and software testing starts only when all parts of the code are ready.

This approach has its advantages and disadvantages. Waterfall allows for better organization of all processes, as they don’t overlap. But since you need to wait until the previous stage is fully complete to move to another one, this approach can also require additional investment of time and money.

Imagine that you create a full prototype of your app at the design stage, and then at the development or testing stage, your team finds a significant flaw. In this case, you’ll need to start all over again, going through the entire codebase and making necessary adjustments, then performing tests again. And as the development budget was already spent on building the complete app, making changes and fixing bugs will require additional resources.

So, for what projects is Waterfall suitable? With the Waterfall approach, a client doesn’t actively participate in the development process (they meet the development team and communicate their requirements when development starts and then usually meet once again when the product is ready), making this SDLC model a good choice for small projects that have strict requirements and don’t depend on external factors like market changes.

Agile model

The Agile methodology is the opposite of Waterfall. This methodology is flexible and allows for changes throughout the software development process, and it suits projects with varying requirements.

The Agile development process is iterative, which means the software product lifecycle is divided into small parts called sprints. The duration of each sprint is about a week, during which a team works on one piece of functionality following the stages of the SDLC. At the end of each sprint, the development team should have new working functionality ready for release. Once a sprint is finished, the development team analyzes the results and plans the next sprint, taking into account possible improvements. Thus, your software’s functionality is developed, tested, and deployed in small batches.

This approach can look a bit messy at first because the stages overlap and repeat during each sprint. But, as sprints have clear timeframes and requirements, the process allows for great flexibility and organization at the same time.

Moreover, it helps to reduce expenses and avoid missed deadlines. As each piece of functionality is tested within a sprint when it is designed and developed, it’s easy to pinpoint flaws and efficiently make changes to the code. In this way, the team spends less time on each piece of functionality and can make necessary adjustments at early stages of software product development, ensuring there will be significantly fewer bugs when software becomes available for end users.

Agile is a winning approach for startup owners, as it allows them to alter project requirements as frequently as they need. Plus, with iterative development, it’s easy to test new ideas, quickly adapt to a competitive market, and change feature priorities.

5. Deployment

The next stage of software development, deployment, contains all processes that make the product available for users. The result of deployment depends on the chosen development methodologies: it can be either a complete app if you’re developing according to the Waterfall methodology, or a new piece of functionality (an update) published in a production environment so people can download and use it if you’re following the Agile methodology. What is the difference in deployment processes between these two methodologies? Let’s take a look.

According to Waterfall, the deployment stage occurs after testing is fully completed. It involves preparation and actual deployment. First, a DevOps collects parts of the code to be deployed and then merges the code into the production environment, after which new functionality is made available to users.

With the Agile approach, deployment is performed continuously throughout all sprints as new parts of functionality are ready. When using Agile, some of the software development practices that play a huge role in successful software deployment are continuous integration (CI) and continuous delivery (CD). These terms refer to the regular integration of new code changes into a central repository and automation of their testing and release processes. With CI and CD, it’s possible to minimize the manual execution of deployment-related processes, effectively merge new parts of code into the software, and ensure their correctness so end users get a high-quality product.

6. Maintenance

Development doesn’t really stop when the product goes live. Once you release your software product, you continue working on it: gather user feedback, analyze it, reconsider the app’s design, implement new functionality, release updates, and repeat. According to the Agile approach, this is the final step in a sprint, after which you start a new one, analyzing and improving the performance of already implemented functionality and working on the development of new features.

Conclusion

The six main stages of the software development lifecycle are planning, requirements elicitation, application design, development and testing, deployment, and maintenance. These stages can go one by one or overlap depending on the development approach you use.

The two most common approaches to software development are Waterfall and Agile. Both can be used effectively, but it’s important to choose the most suitable approach for your project. While Waterfall is a good choice for projects with rigid requirements and a small scope of work, the Agile model is used more frequently. It’s suitable for projects of different sizes and allows you to be flexible in all stages of software development and quickly adapt to a fast-changing market.

Following stages of the software development lifecycle helps you to significantly improve work efficiency, bring clarity into each stage, ensure smooth cooperation of team members, assess and effectively address potential risks and issues, and, as a result, avoid rework and missed deadlines while reducing software development costs.

If you want to know more about how to organize your software development in the most effective way, consult with our software development team. We will help you analyze your project and choose the development approach that suits your current needs and growth plans.