SDLC stands for software development life cycle, a structured process teams follow to plan, build, test, and maintain software.
The stakes are high: only about a third of software projects fully succeed, and unclear requirements drive roughly 39% of failures, which a disciplined SDLC is built to prevent.
It breaks a project into clear phases, typically planning, analysis, design, development, testing, deployment, and maintenance, so work is organized, predictable, and easier to manage. The goal is to deliver quality software on time and on budget, with fewer surprises along the way.
The SDLC is a core concept in software engineering and project management. This guide explains what SDLC means, its phases in order, the main models (like Waterfall and Agile), and why teams rely on it.
Phases of the software development life cycle
The primary technique and approach to software development imply splitting every task or problem into smaller bits, trying to analyze each of them separately.
The same goes for the software development life cycle model, it divides the entire development process into more feasible chunks of work that need to be done. So what are these development phases?
1. Requirements analysis
As the initial stage in software development, requirements analysis presupposes collecting all the available information about an application or solution that has to be finished throughout the current project. Its specifications, target audiences, features, and other crucial aspects are gathered as well as analyzed in order to build a clear plan on how to approach the app.
Planning before working with code helps software development teams, which operate according to the SDLC, visualize each aspect of the future application in greater detail, thereby minimizing the risks while maximizing the end quality.
2. Feasibility study
This software development phase aims to ensure that the requirements analysis resonates with the corporate culture and business goals and will not empty the resources to the fullest.
In other words, the development team evaluates every detail touching upon the future application to establish its feasibility level and make changes if needed.
Usually, this development cycle ends with a self-explanatory software requirements specification document (SRS). It must be approved by the Tech Lead and the client (for outsourcing companies).
3. Designing & planning
During this software development cycle, a team creates the design of an upcoming application, including its user interface, architecture, primary features, cybersecurity aspects, and the rest. Planning serves as the primary preliminary measure to avoid possible miscommunication, repetitive revisions, or the emergence of critical bugs.
As a rule, the output of this development phase is a software design document (SDD) or the Detailed Design Specification (DDS) that provides comprehensive information regarding how and with what means to code the application.
4. Software development
As the software development life cycle and phase, coding involves reshaping the previously built design into the system using a specific set of programming languages, frameworks, APIs, etc.
A team of developers and designers work in conjunction to ensure the best performance, quality, as well as understanding of the target audience’s preferences.
In most cases, this development phase ends with a fully functional and straightforwardly testable prototype, enabling the team to move on to the next cycle.
5. In-depth software testing
It’s the stage when quality assurance specialists get to work and refer to multiple software test types, such as performance, functional, integration, acceptance, smoke, stress testing, etc., to ensure that the final product version will be devoid of critical issues. The result of this software development phase usually defines the future of any application.
Once QA experts are done testing a piece of software, the output of their work is a totally polished and functional app, which is ready for its primary challenge, deployment.
6. Deployment
Deployment means delivering the tested software to the end user. In other words, the development team releases the application for beta testing.
Even though it’s already been scrutinized from all corners, it’s time for the target audience to say their word. The team can move on to release and maintenance only after collecting their feedback.
As soon as all the information is gathered and processed, the team fixes any issues spotted so that the app’s final version can be freely published.
7. Maintenance
Even long after release, any software product needs some updates or new features because there are no better testers than time and real-world usage. Production support engineers, QA specialists, and programmers are responsible for maintaining a piece of software even after it’s been shipped to users.
This phase ending the SDLC, the life of software products continues as long as their functionality satisfies the target audience until the features are deemed unnecessary.
The SDLC models you should learn about
While the software development life cycle is a somewhat abstract project management model, which is always kept in mind and never revisited, there are numerous more specific as well as practice-oriented approaches to building applications.
Nowadays, teams worldwide take advantage of such SDLC models as the Waterfall, RAD, Spiral, V-Model, Incremental, Agile, Iterative, and Bigbang. For more details, look below.
Waterfall model
As a continuous software development model with its phases, it is perceived as a steadily downward process that resembles a waterfall.
Requirements analysis, design, implementation, quality assurance, and maintenance are passed one by one, straightforwardly. Such a linear ordering of workflows has both benefits and downsides to it.
Although the Waterfall model is still one of the most famous approaches to working with each software development life cycle step by step, more and more companies refrain from using its principles as they lack flexibility when it comes to fixing issues or getting approval.
RAD model
Rapid Application Development, or simply RAD, is a software development model that heavily depends on quick decisions. As the name itself suggests, the RAD model prioritizes rapid software development within lesser time. This result is usually achieved by following these development phases:
- business modeling;
- data modeling;
- application generation;
- testing and turnover.
Most often, teams refer to this SDLC model to develop software within 2-3 months when they have precise project requirements and when the technical risks are extremely low.
V-model
The V-Model is another software development life cycle conceptual framework, also known as the Verification and Validation model. Just like many other workflows, it stems from the Waterfall model, having borrowed from it the impossibility of starting a new phase without finishing the previous one.
As usual, your software development team has to know all the project requirements before they start to apply this model, inasmuch as it’s difficult to go back in time and make changes if you opt for the V-Model.
Spiral model
Unlike the previous SDLC models, the Spiral is one of the most flexible methodologies as it heavily relies on the Iterative framework.
Teams that stick to the Spiral model go through 4 phases over and over as they are shaped in spirals, thereby ensuring multiple micro-stages of refining the software. With the help of this framework, you can build customizable apps.
The only drawback is that your development team can make changes infinitely, with the same rounds going on and on until the client is satisfied with the result.
Incremental model
Even though the Incremental model is usually distinguished from others, it’s actually part of the Waterfall conceptual framework, indicating a series of its cycles.
In the context of this SDLC model, all the project requirements are divided into groups, and the team adds functionality with every new phase, which can start even before the previous is complete.
The Incremental software development model allows for cycle overlapping, and each phase serves as the maintenance phase for the previous one, thereby facilitating more flexibility.
Agile model
The Agile methodology is by far one of the most widespread and famous software development life cycle models. Therefore, the whole project is split into small incremental builds, enabling developers to work iteratively, with each sprint lasting from 1 to 3 weeks.
Unlike the Waterfall model, the Agile methodology is more flexible as well as allows for more straightforward software customization on the go because phases are simultaneous.
Iterative model
The Iterative framework promotes an easier start and goes more difficult with each iteration.
Consequently, the team relies on iterations (an exact set of SDLC phases clearly outlined in time), and with each new cycle, the software gets better until it’s finally released by the end of the last iteration.
Notably, the Iterative model is most helpful when the requirements are coherently defined, when your target app is medium- or large-scale, as well as the odds are that a team will need to make changes to the project on the go.
Big bang model
The Big Bang model isn’t like the rest of the software development life cycle models.
It promotes following no specific phases or processes, let alone that only a small percentage of work is dedicated to planning, which doesn’t fit a lot of real-world projects out there. Most resources are employed to program an application straightforwardly, often without even clearly comprehending the project requirements.
In contrast to other SDLC models, the Big Bang framework perfectly suits small teams and pet projects, so software development companies incredibly rarely use it.
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Benefits of the SDLC: Why do teams stick to models?
Each SDLC model has some advantages and disadvantages to it, so it’s essential to know when as well as in what case to apply this or that conceptual framework. If narrowed down and simplified, the use of any of the aforementioned software development life cycles (except the Big Bang) provides the following benefits:
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Optimized scope management. With continually changing project scopes, development teams start lacking motivation and clear vision, which obviously, results in poor performance.
If you apply, say, the Agile model, you’ll have a time-proven workflow before your eyes and written in the documentation. So it’s simpler and cost-efficient to rely on the already conceptualized framework without having to reinvent the wheel over and over again from project to project.
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Fewer risks. Using any SDLC model that promotes an iterative approach to software development adds flexibility to your project execution.
In other words, you’ll be able to lose fewer resources whenever a client wants to add a new feature or make changes to the project under development in case you follow a strict pipeline.
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Challenges are spotted sooner. Since almost every modern software development life cycle model stands on the pillars of planning and designing before implementing, you’ll be able to incorporate a feature only after analyzing its feasibility and value.
In any event, companies adhere to a specific SDLC model because software development continually changes, and clients always change their minds, so it’s good to have a time-proven framework at your fingertips. Your team can always go back in time and use the combination of “ctrl/cmd” plus “z” keys in real life and with actual people. Sounds helpful, right?
Use Program-Ace’s potential to develop quality software
As a leading provider of software engineering services, our team uses various SDLC methodologies to ensure the optimal approach for each project.
At Program-Ace, our focus is on delivering a client-centric experience, tailoring our frameworks and technology stacks to meet the unique needs of each project. Our experienced software engineering services allow for fast, effective changes without compromising quality or putting your project at risk.
Don’t wait, contact us today for more information and take the first step towards delivering your software development project with confidence.