What Is the Software Development Life Cycle? SDLC Explained

Software development life cycle (SDLC) is the term used in the software industry to describe the process for creating a new software product. Software developers use this as a guide to ensure software is produced with the lowest cost and highest possible quality in the shortest amount of time.

There are seven stages in the SDLC and six common models that are used for different projects. In this guide, we'll go through each stage and model to give you an overview of what becoming a software developer entails.

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What is the software development life cycle (SDLC)?

The software development life cycle (SDLC) is the process of planning, writing, modifying, and maintaining software. Developers use the methodology as they design and write modern software for computers, cloud deployment, mobile phones, video games, and more. Adhering to the SDLC methodology helps to optimize the final outcome.

In IT, the term "life cycle" was first used in the 1950s and 1960s to describe the stages involved in developing a new computer system, but it is now commonly used to refer to all stages in the production of any type of software [1]. 

Read more: How to Become a Software Developer | 9 Tips

Why is the SDLC important?

The SDLC is important because it helps ensure that the right people are involved in the right activities at the right times. Using a structured approach to developing software helps ensure that your project will be successful. Some of the SDLC's benefits are:

• Understanding your requirements and the goal of the software

• Identify risks at an early stage

• Plan how you will deliver your solution in stages, such as building prototypes or writing functional specifications

• Measure your progress relative to your goals and ensure everything is on track

7 stages of the software development life cycle

Each stage in the SDLC has its own set of activities that need to be performed by the team members involved in the development project. While the process timeline will vary from project to project, the SDLC generally follows the seven stages outlined below.

Stage 1: Plan and brainstorm.

The first step in the software development life cycle is planning. It's when you gather the team to brainstorm, set goals, and identify risks. At this stage, the team will work together to devise a set of business goals, requirements, specifications, and any high-level risks that might hinder the project's success.

Stage 2: Analyze requirements.

Once you've come up with some ideas, it's time to organize them into a cohesive plan and design. This requires a lot of research and planning to ensure that your final product meets your expectations (and those of your customers). The big step is creating a detailed project plan document and work breakdown structure that outlines the requirements.

Stage 3: Design the mockups.

Once you've got your design plans in front of you, it's time for wireframing and mockups. This step builds upon the planning stage, building out the tasks you need to do in the work breakdown schedule. There are plenty of tools available, such as Adobe XD or InVision, that make this process much easier than ever before.

Stage 4: Develop the code.

The development phase is where coding begins to take place. It is one of the most time-consuming phases in the SDLC. This phase often requires extensive programming skills and knowledge of databases. The team will build functionality for the product or service, which includes creating a user interface and building the database so users can store information in your system.

Stage 5: Test the product.

Before releasing the mockups into final production, you'll need to test it to ensure it is free of bugs and errors. Any issues need to be fixed before moving forward with deployment. You'll also need to manage how the system will integrate into existing systems, software, and processes.

Stage 6: Implement and launch the product.

Once you've completed all testing phases, it's time to deploy your new application for customers to use. After deployment, the launch may involve marketing your new product or service so people know about its existence. If the software is in-house, it may mean implementing the change management process to ensure user training and acceptance.

Stage 7: Set up maintenance and operations.

The final stage of the software development life cycle is maintenance and operations. This is one of the most critical stages because it's when your hard work gets put to the test.

Maintenance involves updating an existing software product to fix bugs and ensure reliability. It can also include adding new features or functionality to a current product. Operations refer to the day-to-day running of a software product or service, such as performing backups and other administrative tasks.

How do I become a software developer?

Becoming a software developer requires learning the key skills, programming languages, and concepts to build software products. It's possible to pivot or switch careers with the help of online learning. Test the waters with IBM's Full Stack Cloud Developer Professional Certificate to learn front-end languages and tools like HTML, CSS, JavaScript, and more.

Take a look at the course and see if it's a good fit for your career goals:

Software development models

There are six main software development approach models available in the market. Each has its own advantages and disadvantages. They are listed below:

Waterfall model: The waterfall model remains one of the most popular process models in software development. Used since the 1970s, the waterfall model is a sequential design process that moves in a straight line from one phase to the next. Developers use this approach when the requirements for a product are well-defined and resources are available. However, it can perform inconsistently if requirements change frequently.

Agile model: The Agile software development process aims to deliver high-quality software early, often, and at a low cost. Agile methods prioritize working software over comprehensive pre-planning and documentation, which can slow the creative process. It is a modern approach with short phases that works well when software requirements are likely to emerge as the development process begins. The Agile model offers more flexibility than the Waterfall model, but it is not always suitable for large-scale projects with complex requirements because it lacks initial documentation.

Read more: What Is Agile? And When to Use It

Iterative model: The iterative model organizes the development process into small cycles instead of a strictly linear progression. This allows developers to make changes incrementally and frequently so they learn from mistakes before they become expensive. Developers get feedback from users throughout the process with the iterative model, so it's ideal for large projects with a strong leadership team.

V-shaped model: Also called the Verification and Validation model, the V-Shaped model allows for simultaneous development and testing. Like Waterfall, this model follows a linear progression, but you only move on to the next stage once the team finishes the previous one. The V-shaped model focuses on documentation and planning so it's ideal for large-scale projects with long schedules. However, the rigidity built into the system only allows for infrequent changes.

Big Bang model: Compared to other software development models, Big Bang has less structure. With this model, developers start working with little more than an understanding of the project requirements. They must figure out things as they go along, as they put most of the resources into the software development stage. Big Bang focuses on getting something working quickly. This approach works well with small projects, where one or two developers can work together to determine requirements and solutions as they code. However, it can be expensive and time-consuming for large projects.

Spiral model: The spiral model combines elements of other models, namely Waterfall and Iterative. Developers work in shorter cycles, and the work within the cycles follows a linear progression. After each iteration, the software gradually gets better. The key advantage of this model is that it helps manage risk very effectively by focusing on small portions of risk at a time and using different approaches based on the risk profile at that stage. This allows developers to make adjustments without compromising the project's outcome. This approach works well in highly complex, large, expensive projects.

New to software development?

If you haven’t yet started your journey as a software developer, you might ask yourself, “Is software development for me?” Here are some signs that this career path might be one that you will enjoy.

• You love problem-solving and logical reasoning.

• You feel at home in the world of technology and hardware.

• You enjoy working with computers and programming languages like C++, Java, or Python.

• You dream of creating a software product that can positively impact people around the world.

As you take your first steps into a software development career, consider potential employers and particular areas of interest. You can specialize in cloud computing or mobile app development or become a generalist who is an expert at applying the SDLC across many types of software.

How to choose a programming language to learn

It may also be helpful to choose your first software language to learn. Languages like C# and Java are still in demand by employers, but many new languages are emerging, too. Before choosing a language, you need to know what you want to code, but simple front-end development languages like JavaScript, HTML, and CSS are good places to start.

Software developer careers and job outlook

Software development is a field where you can be a generalist or specialize in a particular language or software platform. Software developer salaries vary based on their level of expertise and experience. According to Lightcast™, the average annual wage for software developers is $121,375 [2]. Here are some examples of annual base salaries* in the US for different software developer roles:

• Lead software developer: $122,646

• Cloud software developer: $107,899

• Mobile app developer: $70,830

• Full-stack software developer: $71,507

• UX software developer: $108,449

• AI software developer: $102,561

• Python software developer: $89,706

• Java software developer: $88,479

• PHP software developer: $88,783

*Salaries sourced from Glassdoor

Learn about software development from experts

In IBM's Full Stack Software Developer Professional Certificate, you'll build job-ready skills and create professional projects for your portfolio. The University of Minnesota's Software Development Lifecycle Specialization explores traditional, secure, Agile, and lean software engineering development processes.

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