Creating a system that performs complex functions requires more than rock-solid expertise. You need a structured approach that will help you achieve your software development goals as efficiently as possible.
Software development is a long, complex, and tedious process ridden with challenges. Common issues include incomplete requirements, changing project scopes, poor communication, unrealistic deadlines, insufficient testing, etc. If you’re unable to handle them properly, you risk wasting loads of money and ending up with poor-quality software.
In short, diving into the process without a structured approach is a recipe for a disaster. The only way to do things right is with a methodical framework and effective project management.
What is the Software Development Life Cycle (SDLC)?
A common approach to keep things tidy when developing software is the Software Development Life Cycle (SDLC). It’s a general framework for guiding the development process from inception to deployment and maintenance with a high degree of control, accountability, and error detection.
The SDLC is a broad concept providing the overall structure for different methodologies depending on businesses’ needs and preferences. Its core value lies in its ability to serve as a general compass for the product team to manage the development process systematically, with clear goals and deliverables at every stage.
7 stages of the software development process
Typically, the SDLC framework is divided into six or seven stages. They vary across teams and products, but they include similar milestones. Here’s a general breakdown of the process.
1. Problem identification and planning
In software development, everything starts with a problem. When you identify one, you can move on to looking for a solution. Seek diligently because it may already exist on the market, and you don’t want to reinvent the wheel.
When you’re sure you’ve identified a market gap, you can begin setting the foundation for the lengthy SDLC process. The planning stage involves brainstorming, defining goals, and identifying risks. The project’s stakeholders, including the development team, devise a set of objectives and requirements and search for any high-level threats that might hinder the project’s success.
They also evaluate the feasibility of creating the product, revenue potential, the cost of production, and the needs of the end-users. The process is known as the feasibility study and is conducted to assess the practicality of the software project – so that you don’t invest resources in an idea doomed to fail.
2. Requirements analysis
In the second phase, the exploration goes on in a more detailed manner. The focus sharpens on user needs and system requirements – based on the conclusions from the feasibility study.
The development team gathers input from various sources, including customers, internal and external experts, and managers, to define the software’s functional and non-functional aspects and create a comprehensive blueprint for the product.
Typically, the output takes the form of strategic documents, such as:
- a software requirement specification (SRS), compiling all the requirements for the project,
- use case documents (UCS), describing interactions between users and the system,
- a requirement traceability matrix (RTM), ensuring traceability between requirements and various stages of the project,
- a business requirements document (BRD), outlining high-level business goals,
- data flow diagrams, illustrating the process model of a system, etc.
The specific approach and documents used during the analysis depend on the project’s methodology, complexity, and the company’s preferences.
3. Prototyping and designing
With the requirements clarified and organized into documents, you can proceed to the design phase. Here, things get hands-on. Development teams roll up their sleeves and start plotting how the software will look and work.
During the design stage, requirements described in the SRS are transformed into a detailed specification of the design and architecture of a software system. This blueprint, known as the software design document (SDD), serves as a roadmap for the team, helping implement the project in accordance with the previously defined requirements.
The system design can be divided into a high-level design (HLD) and a low-level design (LLD). The former includes a broad overview of the system’s architecture along with its main components and their interactions. The LLD offers a more intricate, technical depiction of the system, defining the specific data structures, algorithms, and interfaces between the software components. The output of the design phase is usually organized into dioramas, flow charts, sketches, site trees, HTML screen designs, and UML schemas.
A common approach involves creating a prototype – a preliminary design or a model for testing the viability of a concept. Prototyping helps to find and fix problems early, optimize the project before development, speed up the whole process, and save production costs.
Decisions made in the system design stage impact the software’s efficiency and user-friendliness and are critical to the project’s success.
4. Creating software
The development phase is the heart of the software development lifecycle. Here, the actual creation takes place, and the system design is translated into source code, forming the first version of the digital product.
Developers analyze the requirements, identify specific coding tasks, and proceed with daily work until they achieve final results, performing code quality testing all the way through.
The software development phase involves several steps or components that may overlap with one another or span the whole process:
- writing code in a programming language or languages that best suit the project’s goals,
- unit testing, i.e., testing each unit or module of the software individually to ensure that it performs as intended and meets the specified requirements (here, the development stage partially merges with the testing stage),
- integration, when different units/modules are integrated to form a complete system,
- debugging – identifying and fixing errors in the code,
- optimizing code for performance, efficiency, and resource utilization,
- creating comprehensive documentation, including comments within the code and external documentation, to facilitate future maintenance,
- version control – tracking and managing changes to the codebase.
5. Testing, bug-fixing, and quality assessment
Software testing comes next in the development cycle, although it is firmly rooted in the previous phase with unit tests and other assessment and error identification procedures.
The actual testing stage involves a meticulous examination of the software to pinpoint and rectify any defects. The goal is to ensure that the system meets specified requirements and is free of vulnerabilities.
The testing phase involves several types of testing, which may differ across projects depending on the methodology and business objectives. Typically, they include:
- unit tests described above,
- integration testing, which ensures that integrated units work seamlessly together,
- system testing for evaluating the system as a whole and delivering high-quality software,
- performance testing, which verifies how the software performs under various conditions (heavy user loads, situations beyond normal operational capacity, etc.),
- acceptance testing that checks whether the software satisfies the acceptance criteria and meets user expectations,
- security testing for assessing the software’s resilience to security threats (examples include security testing, fuzz testing, etc.),
- usability testing, which evaluates the product’s user-friendliness.
Other security assurance activities may involve regression testing, compatibility testing, penetration testing, exploratory testing, and many more, with some being subsets of tests described above.
6. Software deployment
In software development, teams work on a distinct copy of the software, separate from what users access. During the deployment, a user-ready version of the software is installed in the production environment. Keeping it isolated from the build and testing environments guarantees uninterrupted user access during software changes or upgrades.
The deployment phase includes several activities to move the build to copy to production, such as installing and testing the software, configuring the environment, packaging, creating guides for the installation and system operations, etc.
Depending on the development team’s practices, project requirements, and the complexity of the software, the deployment process can be automated. Moving software to the production environment without manual intervention helps to increase efficiency and reduce errors. The initial setup might require additional effort, but it’s a worthwhile investment in the long-term perspective.
7. Maintenance
The software development lifecycle doesn’t end with deployment. You need to continuously attend to the software you’ve released, which makes the maintenance phase an integral part of the SDLC framework.
The purpose of this stage is to make sure that your system is operating according to the specifications and requirements developed in the initial phases. The software must be continuously monitored, maintained, refined, and regularly updated according to the changing business requirements and needs over time.
The maintenance stage serves to ensure that the software remains a top performer by addressing glitches and providing enhancements, such as security patches, bug fixes, performance optimization, and user interface tweaks. You need to make sure your software remains compatible and fully functional with new hardware, operating system updates, or other factors.
The maintenance phase also involves keeping documentation – including user manuals – up-to-date and providing user support. End users frequently report errors that were not caught during the software testing stage, which may generate new stages of development, making the whole software development lifecycle more complex and iterative.
The software development industry is now favoring a more agile approach, with maintenance being just another stage for further improvement and future development.
5 SDLC models
The outline of the SDLC phases provides a bird’s eye view of the software development process, which, in reality, can take many shapes and forms. Specific software development projects are guided by various approaches and frameworks known as SDLC models.
They help project managers and their teams arrange the iterative process and perform development tasks in an organized way from conception to the actual development phase, deployment, and maintenance.
Each SDLC model defines activities and deliverables involved in creating a software product, enabling systematic and efficient management of the software development process at every stage. Here’s a rough depiction of the main development process models.
Agile model
The agile methodology is one of the best-known SDLC models. It’s an iterative approach with a focus on flexibility and collaboration between the development team and the client.
The agile method emphasizes joint decision-making and development over multiple short cycles or sprints rather than a top-down process with a single series of stages.
Software developers focus on the most important features at any given moment instead of just sticking to the plan.
Waterfall model
The waterfall is a traditional software development model and the first established approach to building systems. It differs from the agile model in its focus on linearity and sequentiality.
The waterfall model is suggested for projects with well-defined requirements and a fixed budget and timeline.
Its key strength lies in clarity and commitment to the goal. However, the waterfall model leaves little room for unforeseen changes or revisions.
Iterative model
In the iterative model, the development work starts based on well-defined software requirements, with enhancements added successively through a series of iterations until the final product is delivered.
The iterative model breaks down a larger project project into smaller, more manageable chunks that can be developed, tested, and deployed in shorter time frames. This approach allows for feedback and adjustments, which get incorporated into subsequent iterations.
Key benefits include improved flexibility and collaboration and better risk management. The main con is the complexity resulting from frequent modifications to the requirements and design.
Spiral model
The spiral model is a risk management-focused approach combining elements of the iterative and waterfall paradigms. The model involves iterating through four phases: planning, risk analysis, engineering, testing, and evaluation, in a spiral-like manner until completing the project.
The spiral model’s key characteristic is the continuous assessment of project risks and refining the software with each spiral loop based on lessons learned and risk mitigation.
The strategy is particularly well-suited for large and complex projects where strict risk management is crucial. On the other hand, it may be an overkill for smaller software applications with limited budgets and requirements.
V-model
The V-model, an extension of the Waterfall approach, emphasizes verification and validation. It’s a highly disciplined strategy requiring testing after each development activity.
The process’s structure may be illustrated as the “V” letter, with the left arm consisting of verification steps and the right arm including the corresponding validation stages. The next development phase starts only after the completion of the required testing activity.
Because of its emphasis on thorough testing, the V-model is often used in safety-critical systems, such as aerospace and defense systems. However, advocates of the agile model criticize this approach for its inability to respond efficiently to changes.
Launch your product successfully with a structured approach to software development
The software development life cycle with its SDLC phases serves as the backbone of disciplined and effective software development. Combining this paradigm with an SDLC model of your choice can significantly streamline the project and help you deal with challenges – from the planning stage and architecture analysis all the way to development, code reviews, security assessments, deployment, and maintenance.
If you need a structured path to delivering software that meets both functional requirements and customer expectations, feel free to reach out for consultation!
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