Developing high-quality software demands a structured approach that balances planning, execution, and adaptability. Turning an idea into a functional product requires addressing complex requirements, tight timelines, and user expectations.
To tackle these challenges, organizations use the software development lifecycle (SDLC), a proven framework designed to ensure efficiency, consistency, and quality throughout the development process.
In this article, we will be discussing why the SDLC is important, the stages of the lifecycle, and the most important and common models.
Besides developer expertise and engineering resources, quality software is the product of reliable processes. In technical terms, those reliable processes are known as the software development lifecycle (SDLC).
The software development lifecycle (SDLC) is a process for coding, designing, and managing software. It comprises several methodical stages prioritizing increasing system efficiencies, proper planning, and rigorous testing. SDLC enables organizations to produce the highest-quality software in the shortest possible time while minimizing costs.
The SDLC presents a way of remedying some of the software development challenges. These challenges, which are an unstable technology landscape, changing user/client requirements, and limited engineering resources, hinder the deployment of quality software. Hence, SDLC is necessary for the following reasons:
Typically, there are six phases or stages of the Software Development Life Cycle, which are as follows:
The SDLC begins with senior team members collecting requirements from the project’s stakeholders, determining its feasibility, and planning a basic approach. This stage should clarify the project's scope and any anticipated issues, risks, and opportunities.
This stage requires input from business analysts, finance teams, and project managers. The goal of this stage is to brainstorm and lay a foundation for the project’s success.
To make things easier to understand, let’s imagine that a development team needs to build an Identity Access Management (IAM) software. They’ll begin by meeting to get basic details about the product, like:
Once the requirements have been gathered and analyzed, the next stage is defining and getting them approved by stakeholders. At this point, the project’s timeline, cost, scope, and every other information agreed upon in the previous stage are finalized and documented in the Software Requirement Specification (SRS) document. The goal of this stage is alignment with all stakeholders, after which comes the technical aspect of building the software.
Using the example from the first stage, the development team ensures that the stakeholders agree on the requirements and documents them for reference.
This stage is like creating a house's building plan. System architects work with the SRS to determine the product's best and most cost-effective architecture. Then, designers create the software’s interface while product managers review the plans to ensure they align with the business’s objectives.
Typically, more than one design is proposed and documented in a Design Document Specification (DDS), with the most optimal one selected according to timeline, robustness, and cost. The goal here is to create a blueprint for developers to work with when writing the software's code.
For the team working on an IAM software, it’s at this stage that they map out and design the different components of the product, some of which are:
This is when the product is built. Developers generate the programming language code according to the DDS and follow the organization’s coding standards and guidelines. They must also complete project modules and new features within established deadlines. The goal is to build functional software that meets user requirements.
At this stage, using our example, the development team will develop functional IAM system modules and unit-test the code to ensure it matches the blueprint.
As each component of the software build is completed, it’s sent to the testing team, where it’s thoroughly tested to ensure it’s working as expected. Any defects are documented and sent back to the development team for correction. The goal here is to deliver bug-free software.
An IAM software will need to undergo tests for different purposes, such as functional testing, integration testing, security testing, performance testing, and User Acceptance Testing (UAT).
Once the first version of the software has been tested and any defects removed in the production environment, it’s delivered to a large group of end-users, who will often discover undetected bugs and errors from the testing stage.
This is when the IAM software goes live with activated login portals, admin and user documentation, and any other details the client needs to launch with the software’s first version.
Thereafter, developers will incorporate any user feedback into the software's next release, as part of the maintenance stage. Security patches and feature enhancements are also maintenance activities.
Now that we have a clear idea of the structure of the software development lifecycle, how do you navigate these different stages while building software? Must they always be done sequentially? The next part of this article answers these questions.
The SDLC consists of different models, which are frameworks for developing software. They are:
The oldest and most straightforward software development model gets its name from its linear beginning-to-end flow. Each stage follows its plan and must be completed before the next stage can begin, with one stage waterfalling into the next.
Pros:
Cons:
Best for: small teams, highly regulated industries, projects with fixed budgets and timelines.
In the iterative model, the goal is to build first and make improvements over time. Rather than aiming to produce a fully developed application at once, developers quickly create an initial version of the software and improve it with successive small iterations.
This approach is ideal for creating larger applications. It allows development teams to break the project into manageable chunks and quickly deploy software to users.
Pros:
Cons:
Best for: projects with tight timelines, changing requirements, and software whose core features can be delivered first.
Using the iterative approach, the agile model divides the project into multiple cycles and delivers several releases. Each release generates feedback incorporated into the next release, allowing organizations to quickly adapt to an ever-changing market while reducing risks particular to the waterfall model.
Pros:
Cons:
Best for: early-stage startups, DevOps teams, and projects requiring flexibility and collaboration.
The spiral approach combines elements of the waterfall and iterative models. It repeats the planning, design, build, and test stages of development in linear succession, making iterative improvements with each pass through the process.
Pros:
Cons:
Best for: ideal for large and complex projects with high-quality standards, like military or healthcare systems.
The V-model, also known as the verification or validation model, extends the waterfall model by incorporating testing at each stage of development rather than including a standalone testing stage at the end.
Pros:
Cons:
Best for: small projects with clear requirements.
This approach minimizes formal structure and processes, instead relying on large amounts of time, effort, and resources to produce software. It is the highest-risk model and best suited for small teams.
Pros:
Cons:
Best for: short-term low-risk projects and projects with evolving requirements.
The following SDLC best practices will simplify each SDLC stage, improve code quality, and ensure successful software deployments:
Building and maintaining software is not a walk in the park. Without clear objectives and processes, your software project risks getting derailed, with no clear way to get back on track. Following the SDLC stages and working with the right model ensures you can build the software you envision that perfectly meets your customers' needs from the outset.
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