What Is the Software Development Life Cycle? A Comprehensive Guide

Software development can be a tricky process, and it’s easy to make mistakes if you don’t know what you’re doing. The Software Development Life Cycle is a process that a software development company follows to create new applications.

While it is possible to build apps without following an SDLC, the process is more cost-effective and time-efficient when it follows a structured approach. The software quality also depends on how well you follow this structured development plan.

This article will help you understand the Software Development Lifecycle and how it works so that your next project will have fewer problems and your product can sparkle with higher customer satisfaction.

• The Software Development Life Cycle (SDLC) is a structured, step-by-step process for creating software applications.
• A well-structured SDLC improves planning and reduces the risks associated with development. It also provides a framework for resource allocation and ensures that you end up with high-quality software.
• The SDLC process consists of seven key phases: planning, requirements analysis, system design, implementation (coding), testing, deployment, and maintenance.
• SDLC models and methodologies offer a distinct approach to executing the development phases. Modern SDLC practices also incorporate supporting elements like DevOps and CI/CD to enhance efficiency.

What Is the Software Development Life Cycle (SDLC)?

The software development life cycle is a concept used to define the entire process of building a software product step by step, from start to finish. It is a detailed plan that serves as a structured framework for a development project. Engineers use the SDLC as a guide for the project from concept to deployment. It also contains instructions for maintaining and improving the quality of the software.

The SDLC process breaks the entire software development project into distinct phases. Each phase has clear, repeatable, and independent steps, with clear goals that must be delivered before moving to the next phase. When combined, all the phases of the SDLC provide a comprehensive roadmap that the development team can follow to create high-quality software that meets all the standard requirements.

Software Development Life Cycle models can be either sequential or iterative. A sequential model, like Waterfall, follows a strict order of phases from initial planning to final delivery. In contrast, an iterative model, such as one used in the agile software development methodology, repeats the development phases in shorter cycles or sprints.

Benefits of Using SDLC

SDLC is an approach to software development that designers and engineers can follow when developing a software application. Following this process introduces structure to an otherwise complex task of bringing a software idea to life. The following are some of the benefits of formalizing the software development process with an SDLC.

Improved Planning

Software development involves balancing multiple factors, from user preferences to stakeholder needs. The interaction between all of these factors may cause requirements to change repeatedly as you progress, causing lost time and increased complexity. The software development life cycle creates a systematic framework for managing everything. This way, engineers, solution architects, and other stakeholders have clear knowledge of the goals for each phase and the steps they need to complete to achieve them.

Risk Reduction

The Software Development Life Cycle helps to mitigate the massive risks inherent in today’s software design and programming. It eliminates guesswork so it ensures that everyone involved knows ahead of time what the project requires, so there are no surprises later on during production, which can cause lots of problems! This reduces the risk of the project failing and reduces the cost of future work.

Better Resource Management

In software development, decisions have to be made on how to balance the allocation of resources among the different components of the project. The SDLC provides a framework for allocating these resources. This facilitates a more streamlined development process where the resources are optimally utilized and the project stays within budget.

Higher Quality Output

The SDLC makes the development and testing process more structured. Designers and engineers get to cover every base while aligning the product to user needs and business requirements. This promotes the creation of a high-quality, error-free software product.

Greater Predictability

The SDLC model introduces clarity and predictability. The software development project is divided into phases, with clear activities and deliverables for each stage. This makes it more likely to predict how much time, resources, and other factors will go into each phase.

Phases of the Software Development Life Cycle

In the production environment, quite a few development stages need to be completed in order to create a full software development project. Although different teams may define the phases of a complete project in different ways, most experts agree on an SDLC with seven key phases. The details of each of these phases are summarized below.

1. Planning & Feasibility Study

The planning phase is where the software development team, together with business analysis experts, decides what features the software must have in order to meet business requirements and customer needs. These become the main objectives of the project and the foundation for creating a plan.

Additionally, they also need to map out the processes that need to be completed for the project to succeed in line with the software development goals. Feasibility analysis, which may involve examining the technical, operational, and economic requirements of the project, will also be carried out. This will ensure that the high-level goals that will be set for the project are practical and achievable.

2. Requirements Analysis

For the next phase, the engineers will begin to gather the technical and non-technical requirements for the software project. They do this by interviewing customers and other stakeholders. They may also organize workshops and consult documentation provided by various teams.

Engineers gather technical and non-technical requirements by interviewing stakeholders, organizing workshops, and consulting documentation. This information is compiled into a Software Requirement Specification (SRS) document, which details everything that needs to be implemented.

3. System Design

The system design phase is where the team begins to define the project architecture and the tools that will be required to create the software functionality. To do this, the goals and requirements of the projects are analyzed to create concrete and detailed designs.

Visual modeling tools like UML, wireframes, and ER diagrams are used to create a blueprint of what the software is expected to look like and how it’ll work. In addition to creating visual designs, this stage also involves defining the tools or tech stack that’ll be needed to bring the designs to life. Key technological decisions, such as how the new product will integrate with existing infrastructure, will also be made at this stage.

4. Implementation (Coding)

This phase is where everything begins to come together. In the coding or implementation phase, the engineers set up the development environment and use the programming languages and other tools specified in the system design phase to write the software code. Every step of this phase is carried out in line with the SRS and other guidelines that have been established during the previous phases of the project. The development must also follow best practices, including consistent code reviews, version control, and proper documentation. Managing the software development cost effectively during this phase is crucial to keeping the project within budget.

5. Testing

In the testing phase, the software is tested to ensure that it works as expected. Depending on the SDLC model being used, the testing phase may overlap with the development stage of the project. This means the development team might carry out code reviews and tests while still coding the rest of the project.

With some models, the testing phase is a standalone stage carried out after a fully functional piece of software has been developed. The goal is to create bug- or error-free software while also ensuring that the product is fully aligned with the project requirements.

The software developers who wrote the code should test their work and have other team members do so as well in order to find bugs or other issues with the product. Once these are fixed, testing is then carried out by a wider audience. The product should go through all kinds of system testing, including:

• Acceptance testing
• Unit testing
• Penetration testing
• Integration testing and so on

Before it goes live, these tests examine different parts of the software to confirm that they work as intended.

Software tests often include manual and automated testing methods. With automated tests, the software is scanned automatically by an advanced system and tested with different cases to uncover potential bugs. Manual tests are also carried out by human testers or QA teams to see the software in action in various real-life scenarios. To ensure nothing is missed, the testing stage itself is guided by a framework known as the Software Testing Life Cycle.

6. Deployment

The deployment stage is where the developed software goes live, which means that it becomes available for use. The previous stage should completely prepare the software for launch. Software developers and project managers, as part of a project team, may have to undertake activities such as configuring servers with settings and security features before making the product accessible to end-users or customers.

The project may be deployed first in a staging environment, which simulates live scenarios and allows developers to carry out final tests. After these, the product is then pushed into the production environment, where it goes live for the general public. Depending on the type of product and the project goals, the software can be deployed on local servers on-premises or hosted on cloud platforms.

After this development process stage has been completed successfully, the project can be closed, along with all necessary documentation being archived in case the product has to be maintained or enhanced at a later date. That is a very common step in the development life cycle methodologies.

Development teams follow different release strategies to roll out a product. With the canary approach, the version ready for release is first rolled out to a small group of users before it is made available to everyone. This is another strategy that helps the team test the product version one final time before it goes fully public. There’s also a blue-green software deployment approach where two identical production environments are maintained simultaneously for the new and old versions of the software. This way, the new version is thoroughly tested before it is switched on.

7. Maintenance & Support

The maintenance stage is often omitted in the process, but it should be a part of the development of any software project by all software teams. As software is used over time by end-users or customers, it may need to be changed or adapted in the software development process.

Software developers make these changes and updates in the maintenance phase after deployment has been completed successfully. If necessary, they will go back to one of the previous stages, such as the planning or design phase, if further research needs to be done before the changes are made.

Common SDLC Models and Methodologies

To execute the different phases of a development lifecycle, software engineers can choose between different models or methodologies. Each model is a distinct approach that defines how the phases of the project should be executed. The ideal methodology for any project depends on the complexity, available resources, flexibility, and several other factors. The following are some of the most popular SDLC models.

Waterfall Model

The waterfall model takes a linear or sequential approach to software development, where each development phase leads to the next one. With this model, there’s no overlap between the development stages. A new phase only begins after the previous one ends.

Given the simplicity of this model, the waterfall methodology is best suited for small, well-defined projects with straightforward requirements. The biggest challenge with this methodology is its rigidity. Also, since testing is only done after a phase has been completed, errors or bugs in the product are often difficult to fix.

V‑Model

The V-Model takes a parallel approach for implementing the development phases. It is essentially an extension of the waterfall model, but it introduces a corresponding testing phase for each development stage of the project, forming a V-shaped model.

This SDLC methodology is also called the Verification and Validation model. The Verification aspect of the model aligns with the development steps, while the Validation aspects correspond to the testing steps. The goal of this model is to ensure that the right product is built (validation) and it is built correctly (verification).

The V-Model is a robust methodology suitable for complex projects. However, since it is an extension of the waterfall model, it is subject to the same challenges, including a lack of flexibility. While test execution happens after the corresponding development phase is complete, a key feature of the V-Model is that test planning and design occur in parallel with each development stage, which helps uncover issues earlier than in a pure Waterfall model.

Spiral Model

The spiral model introduces some flexibility to the conventional waterfall model by adopting an interactive approach. As the name suggests, the SDLC processes in this model are represented by a spiral diagram, with each forming a loop. The spiral SDLC model is primarily risk-driven. Each iteration of the software involves significant risk analysis and mitigation. The project only progresses to the next iteration after high-priority risks have been assessed and resolved.

Iterative and Incremental Model

The iterative model is a development approach that involves creating the software in small incremental steps. Each iteration follows specific requirements, after which the software is reviewed and tested. The feedback from the previous iteration is used for the subsequent versions of the software. This way, the software grows progressively and adapts to changing requirements. Breaking the entire project into shorter iterations also makes it easier to test and debug issues. The iterative model requires careful planning and close monitoring for each iteration.

Agile Methodology

This is arguably the most popular SDLC methodology. Ironically, Agile isn’t a software development life cycle model in the traditional sense. Instead, it is a set of software development principles that prioritizes adaptive planning, continuous collaboration between teams, and evolutionary development.

With the Agile methodology, the entire project is broken down into several cycles or sprints, with each cycle passing through some (or all) of the individual SDLC phases. Agile emphasizes collaboration between teams and stakeholders.

Customer satisfaction is one of the core principles of this model, which is why this approach often focuses on regular cycles of feedback and iteration. The benefits of Agile methodology include increased flexibility, faster delivery, and improved product quality. Several sub-methods have been developed based on the principles of agile development. Examples include the Scrum framework, Kanban, and Extreme Programming (XP).

Rapid Application Development (RAD)

The RAD model is an SDLC process that prioritizes speed and efficiency. The main goal of this approach is to save time by breaking large projects into smaller projects that can be planned out and completed individually. The individual components can then be integrated to complete the entire project.

In addition to taking this interactive approach, the RAD model also prioritizes feedback from stakeholders throughout the development project. This ensures that the final product is fully aligned with user expectations.

Lean Software Development

Lean is a development ideology whose origin can be traced back to the manufacturing industry. This system, which focuses on making more with less, has been adapted to the software development industry as well.

The Lean methodology focuses on increasing development speed while decreasing production cost. This strategy identifies factors that waste time and effort and seeks to eliminate them. For instance, Lean discourages multitasking. Instead, the team focuses on present tasks. This reduces time and effort wasted on unnecessary documentation, meetings, and planning.

Big Bang Model

The big bang model is an SDLC methodology that requires little to no planning. Development begins right after gathering the necessary requirements for the project. Also, instead of breaking the project down into phases, everything happens simultaneously, similar to traditional software development. This approach is high-risk and full of uncertainties, which is why it only works for simple projects or prototype development.

Supporting Elements of the SDLC

The SDLC is supported by other processes or additional components that are not part of the core framework. Yet, these supporting elements are necessary to enhance SDLC implementation. Here are a few of these additional components.

Software Architecture & Design Patterns

One of the core choices IT teams have to make while planning an SDLC is to determine the fundamental structure of the software. The simplest approach is to treat the software as a monolith by combining all of its components into a single unit. This approach works for simple projects but may be difficult to maintain for larger or more complex projects. In contrast, they can also follow a microservices architecture, where the entire application is broken down into smaller deployable components (or services) that are built independently before being integrated.

The design pattern is another vital supporting element of the SDLC. This can come in different forms, from Model-View-Controller (MVC) patterns (distinct layers for information display and user interactions) to Singleton patterns. Overall, the architecture and design of a software project determine the overall quality of the code and how easy it’ll be to maintain. Following these plans is also necessary to maintain consistency throughout the development process.

Documentation

Software documentation is a vital component of the software development lifecycle. Proper documentation not only shows how the software functions, but it also provides vital information for future maintenance and upgrades. Some essential documents associated with the SDLC include design documents, SRS, user manuals, and maintenance logs.

Estimation & Risk Management

A properly planned SDLC maps out every aspect of a project. Time and resources are planned to the last detail, with story and function points assigned to each component. This helps to mitigate risk and reduce the chances of unforeseen challenges. However, even the best planned SDLC may still encounter issues. From unexpected bugs to employee issues or resource constraints.

This is where proactive risk assessment comes in. It involves analyzing all the critical components of the project and identifying potential failure points. Based on these analyses, you can proactively create backup plans for the most important possible failure points. It is also important that every software development plan includes some headroom for unforeseen circumstances.

Stakeholder Management

Every software development project involves multiple people. From developers to designers, product managers, product owners, and even external stakeholders such as investors or end-users. A good development plan considers all of these stakeholders and includes clear plans to maintain continuous communication. This ensures that every phase of the project remains fully aligned with stakeholder expectations and user requirements. Proper communication prevents major issues such as scope creep and user dissatisfaction.

DevOps, CI/CD, and SDLC Integration

In modern software development, the SDLC isn’t a standalone concept. It incorporates other supporting practices such as DevOps, CI/CD, and Infrastructure as Code. These practices make the SDLC more efficient by breaking down the silos between different phases of development, enabling faster and more efficient software delivery. Here’s an overview of some of these practices.

Continuous Integration & Delivery

Continuous Integration and Continuous Delivery (also known as CI/CD) are two separate but closely related concepts that help automate the process of integrating, testing, and deploying code, so it’s faster and error-free. CI is concerned with automatically testing code changes made by multiple developers and continuously merging them into a shared repository. This improves collaboration while also ensuring that bugs are caught early on.

Continuous Delivery, on the other hand, is focused on preparing code for release. It automates the process of deploying code to the staging environment for further testing and promotion to a production environment.

CI/CD ensures that changes to the software code are integrated and delivered continuously. This can potentially shorten the entire development lifecycle. It also shortens and automates several steps in the deployment process, reducing manual error.

DevOps Culture

DevOps is an approach to software development that focuses on continuous collaboration and communication between the development and operations teams involved in software development. Combining this development approach with the SDLC drives faster and more efficient software delivery.

With the DevOps approach, cross-functional teams contribute to the overall efficiency of the software development lifecycle. This approach is particularly focused on the building, testing, and deployment phase of the SDLC. It streamlines and automates critical processes in these stages to improve delivery speed and overall quality of the software.

Infrastructure as Code (IaC)

IaC is the practice of defining and managing the infrastructure needed for software development as code instead of manual processes. This practice creates consistent and fully automated environments, which can speed up the deployment phase of the SDLC. In addition to accelerating deployment, IaC also improves the consistency of your development infrastructure and reduces errors.

Security in the Software Development Life Cycle (DevSecOps)

DevSecOps seeks to solve one of the problems associated with conventional software development. With the traditional approach, security-related issues are often left until the testing phase of the project, after all the critical design and development have been completed. The problem with this approach is that complex security issues may go undetected. Even if they are, they’ll cost more to fix.

DevSecOps is a framework for secure software development that integrates security into every phase of the SDLC. This way, the IT team can identify security issues early on and avoid costly rework late in the development process. Some of the security measures associated with DevSecOps include following secure coding practices, comprehensive threat modeling, and compliance with regulatory standards such as OWASP and ISO 27001.

Tools Used in the SDLC

The Software Development Life Cycle is an iterative process that requires more than just one tool. This makes it difficult to pinpoint which tools should be used in each phase of development, as there are multiple ways to complete each task. For instance, software developers may use a tool like GitHub and its pull requests feature during code review, while they might prefer JIRA for issue tracking when it comes down to QA testing the software before pushing it into production. Below is a list of the different types of tools commonly used across different phases of the SDLC:

• IDEs (e.g., VS Code, IntelliJ) – Integrated development environments like VS Code and IntelliJ are used in the build phase of the SDLC. They are mainly used for writing, editing, and debugging code. IDEs support various programming languages and frameworks, which makes them perfect for large-scale software development projects where developers have to build different components using different languages.
• Version Control (Git, GitHub, GitLab) – Development teams use version control tools like Git, GitHub, and GitLab to manage any changes made to the software source code. Version control tools track revisions, allowing developers to create branches or merge different software versions into one. They’re also a valuable collaboration tool for large development teams.
• Testing Tools (Selenium, JUnit) – Before deploying software, developers carry out unit, integration, and performance tests. Testing tools like Selenium and JUnit are useful for automating and managing tests. The specific tools to be used for this phase of the life cycle depend on the type of test that is being carried out.
• CI/CD Tools (Jenkins, GitHub Actions) – CI/CD tools like Jenkins and GitHub Actions automate the processes of continuous integration, delivery, and deployment within the SDLC. These tools accelerate development while ensuring optimal code quality.
• Deployment Platforms (Docker, AWS, Azure) – After building and testing, IT teams deploy the completed software to cloud-based platforms like AWS, Docker, and Azure. These platforms provide the computing resources needed to host the software on the internet.
• Monitoring Tools (Datadog, New Relic) – Tools like New Relic and Datadog handle the post-deployment phase of the SDLC. These apps have features for tracking application performance and monitoring servers. They provide insights into key metrics that can be used to determine and improve system health.

Software Release Lifecycle

The software development life cycle ends with the release of the software for end users. This phase typically happens in a series of steps now known as the software release lifecycle. The SRLC refers to the various stages that the software has to pass through after it leaves the development phase. The details of the concepts of the release lifecycle are summarized below:

• Pre-alpha, Alpha, Beta – Before software is rolled out to the general public for the first time, it passes through the pre-alpha, alpha, and beta stages of testing. Software in its pre-alpha stage has all of its core functionalities in place, but isn’t quite ready for public release yet. In this phase, the team validates the core functionalities of the software and carries out internal unit tests. The tests confirm that the software’s features align with the specified software requirement specification and work as intended.
  As development wraps up, the product moves to the alpha phase, where a small internal team carries out tests in a controlled environment to identify and fix any bugs. These tests confirm the performance, usability, and stability of the app. The software can be refined further based on the results of the tests and feedback from the testing team.
  The beta phase is where the software is tested in a production environment by external users. The software is essentially live at this stage, but only for a selected group of users. This is done either through closed testing (invitation only) or an open testing system where anyone can join in.
• Release Candidate (RC) – The release candidate is the first version of the software to be released and monitored in the wild. However, before the product is released, the team may still carry out some last-minute tests and fix any minor bugs and performance issues that may be identified. This phase is also used to finalize the product documentation, support resources, and marketing materials needed for the rollout.
• General Availability (GA) – As the name suggests, this is the phase of the release where the product becomes available to the general public. From this point on, the team focuses on distribution and ongoing maintenance for the product.
• End-of-Life (EOL) Policy and Planning – An EOL policy is required for managing the rollout of a product that will be discontinued or no longer supported. While this isn’t part of a typical release lifecycle, it may come up during the maintenance phase of the project.
  Instead of simply pulling the plug without a plan, an EOL policy helps an organization to manage resources and maintain customer relationships. This policy provides a detailed plan for when and how support will be withdrawn. It may also include migration plans if users will be moved to an alternative product or a new version of the same product.

Industry Standards and Frameworks

The Software Development Life Cycle (SDLC) provides a blueprint for building software. But each organization gets to choose how to implement this framework for its product. To standardize this process and ensure consistency across the board, a few globally recognized frameworks have been introduced. These standards provide stringent recommendations and guidelines for implementing SDLC practices, especially in large-scale environments. Examples of these standards include:

• ISO/IEC 12207 – This is an international standard for Software Life Cycle Processes. It is mainly used to maintain consistency and transparency in large organizations and government contracts.
• IEEE 1074 – This standard, created by the Institute of Electrical and Electronics Engineers, provides a detailed framework for the software development process. This comprehensive standard provides specific guidelines for implementing each phase of the SDLC.
• CMMI – The Capability Maturity Model Integration is an international standard for performance improvement that can be applied to the Software Development Life Cycle. It provides a standard framework that an organization can use to measure the maturity of its processes so they can identify weaknesses and make the required improvements.
• SPICE (ISO/IEC 15504) – Similar to the CMMI, the Software Process Improvement and Capability Determination framework can also be used to assess the maturity of the software development processes.

Emerging Trends in SDLC

The SDLC is constantly evolving in response to the changing needs of the software development industry. As new technologies emerge, SDLC practices will likely change accordingly. The following are some of the current and future trends shaping how SDLC is evolving.

• AI in Software Development (Code Generation, Test Automation) – Artificial Intelligence is becoming increasingly popular in software development as new generative AI tools that are capable of writing or modifying code emerge. This technology has also demonstrated usefulness across other phases of the development lifecycle, from gathering requirements to automating tests and other repetitive tasks. This technology will help simplify SDLC implementation while also boosting the efficiency of the entire process.
• Low-Code/No-Code Platforms – This is another trend that promises improved efficiency since it makes it possible to create software products with little to no manual code. This opens the door for non-technical users to participate in the most critical phase of the software lifecycle. These platforms also allow users to build applications faster while cutting costs. While LCNC simplifies development, it may introduce new challenges, particularly with deployment and ongoing maintenance of the software.
• Edge Computing and IoT – These technologies relate to the functionality of software within the physical world and its interactions with other devices or network systems. This introduces an added layer of complexity to development projects since the software engineering team now has to modify software design, testing, and deployment accordingly.
• Blockchain Integration in Development Processes – Blockchain integration in software development will change the direction of the development lifecycle, particularly in the area of requirement gathering. In designing a blockchain-integrated system, new requirements related to unique blockchain features like immutability, consensus mechanism, and tokenization must be put into consideration.

Common Mistakes and How to Avoid Them

In implementing a software project, there are certain pitfalls that may affect the efficiency of your SDLC framework. Some of these mistakes are highlighted below:

• Being too rigid about methodology – The most suitable approach for a project depends on the peculiarities of the product as well as business needs. Some projects simply won’t fall neatly within any methodology, which is why you should leave some room for flexibility.
• Skipping requirement analysis – Project requirements aren’t just wishful thinking. They must be duly scrutinized to ensure that they’re practical and feasible. The software engineering team must thoroughly understand the requirements and ensure it is fully aligned with stakeholder expectations.
• Lack of documentation – You need to implement effective documentation since it is crucial for security and ongoing maintenance of your product.
• Overengineering – Avoid focusing excessively on automation, tools, and checklists. Prioritize human inputs and team engagement.

Conclusion

A well-structured SDLC provides a roadmap for navigating the complexities of software development. By breaking down entire projects into clear and logical phases, you can manage the process better, maintain clear communication, and proactively mitigate risks.

However, organizations also need to adopt industry best practices and globally recognized standards in order to maximize the benefits of the SDLC. The most successful organizations consider the SDLC as more than a static blueprint. This is why they’re always looking to evolve and incorporate emerging trends into the development lifecycle. This requires a culture of ongoing learning, where teams are encouraged to experiment with new tools and adapt accordingly.

Ready to apply a proven, strategic approach to your next software development project? Partner with a team that understands the full scope of the SDLC. Contact us now to learn more.