SDLC (Software Development Life Cycle) is a framework that is used by companies to create high-quality software in a systematic and cost-effective manner. The SDLC method is used by both small and large-scale companies. The development models of SDLC range from agile to waterfall development, and the teams have the freedom to choose the SDLC model depending on the nature of the project they are taking.
Each SDLC model comes with seven phases used for the design, development, deployment, and maintenance of the software. Today we are going to learn about these seven SDLC phases and their importance in creating robust software.
The Seven Phases of SDLC
When a developer is working on a project, they often think about a single SDLC phase. But for the project to get the best out of each developer, everyone in the software development team needs to know about the other phases and their importance. Here, we have briefly described each of the seven phases of SDLC, and how they fit the bigger picture of software development.
1. Defining Requirements
The first phase is all about getting information about the project. The data is collected from the client who has asked to develop a product for their business. Any of the rising ambiguities need to be answered here in this phase only. This phase may take some time because, before the planning and development start, the development team wants to churn out all the requirements and expectations from the client’s end.
A developer need not rush in this phase as it is better to first understand all the requirements, make a plan, and then start the project. This will make it easier for both the designers and the software developers to understand the project’s result beforehand. In this phase, the project manager should ask the following questions to the client to understand what they expect from the project.
- What is the market in which the application will be used?
- The age group of the user?
- Is it a mobile application, computer software, or web application opened within a browser?
These are just a few examples of the questions which the project head needs to ask during the meeting. The answers to these questions will provide the core understanding and the knowledge of the product which needs to be developed by the team.
In some cases, the planning comes before or with the requirement phase. But we believe that planning needs to start after understanding the client’s requirements. During the planning phase, the project head needs to finalize the team members and the technologies for the project development. Likewise, in this phase itself, the goals and deadlines for the project should be decided. The three main activities of the planning phase are:
- Identification of the technologies used for development: Finding out the right technology is an essential task that a project manager needs to do. The client might ask for the programming language that would be used in the project. Therefore, it’s the project manager’s responsibility to find out the best programming language. This will not only expedite the development process but also provide the elements and the functionalities that are required by the client.
- Feasibility assessment: Before the manager and the company accepts the project, they need to look for the practicality of the proposed project, such as economic, technical, and legal factors of building the product. Moreover, a company needs to be ready with a contingency plan also. This will keep the company safe from any unforeseeable circumstances.
- Creation of the project’s roadmap: The manager now has to set the time frame for the project completion, and divide the task between the team members. Once the planning is done, the project starts with designing and prototyping. After that comes the development part, and other phases follow. But there are different types of SDLC models. After working out the project’s feasibility, the next important thing to do is find the model which the team is going to use for the project. A software development team can easily handle the project if, in the planning phase, the manager has chosen the suitable SDLC model.
3. Designing and Prototyping
The designing and prototyping of the project is a way to chalk out how the product will work and the different features that need to be embedded in the product. The designing and prototyping go hand in hand, and a prototype is nothing but an early version of how the product will look and perform once it is fully developed. In addition, the prototype gives the idea of the user flow to the developers.
Given below are the six different aspects of the product which needs to be addressed in the designing and prototyping stage:
- Architecture: It is also known as wireframing. It’s a method of defining the user flow, location of buttons, and what they will do once clicked. Also, the locations for images, brand logos, and videos can be fixed while working on the wireframing.
- User Interface: UI is an essential part of any software. If the UI is great, half of the user retention problems will be gone. A UI will showcase how the customer will interact with the software and how the product will respond to the inputs filled by users.
- Platforms: Defining the platform from which the application will be operated. The platforms could be multiple or specific, like iOS devices only. The integration with different platforms depends on the client’s requirement.
- Programming: Here, the designers need to sit with the developers and find out how a particular task will be performed by the application and make its UI more intuitive.
- Communication: Define how the product is going to communicate with other applications. For example, if it’s a social platform, how will it upload photos from local storage or Google Photos.
- Security: Defines different security measures to keep the application’s stored data safe. The security features include SSL certificates, password protection, two-way authentication, etc.
Moreover, once the design and the prototypes are made, the stakeholder can see how the product will look and function in a real-world environment. Likewise, clients give their inputs about the design and ask for changes if they don’t like it. It is less expensive to make changes in the prototype phase than to re-write the code in the software development phase.
4. Software Development
Once the design and prototype of the product have been finalized, the production moves to the next phase, software development. In this phase, the team members will use different code writing techniques to turn the design and the project’s requirements into a working application. This is the first stage where you start to see the application which resembles the final product.
Once this phase is complete, the project team will have a working feature of the client’s requirements. Developers are the driving force of this phase, and during the development process, they will be in touch with the client and the testers and ask for their inputs. Most of the writing of the code happens in this phase. A single developer can write a small project’s code. While for a larger project, a team of software developers will be creating specific elements of the project, and then combine all of them to develop a complete application.
A software developer heavily relies on the instructions and the explanations which the client and the design team document. Apart from the software development, in this phase, the product’s documentation is also created. Documentation could be a quick guided tour in the form of a video or presentation that showcases the application’s basic features. The documentation is developed to solve problems or technical questions.
In the Testing phase of SDLC, the company focuses on the investigation and discovery of errors and loopholes in the development and designing of the product. The testing phase will help developers know whether their code is performing according to the product’s requirement or not. Of course, it might not be possible for a developer to solve every single error which surfaces in the testing phase. But the results from this phase can be used to reduce the number of errors that could occur in the application’s functioning.
The three main types of testing done in the testing phase of the SDLC are:
- Quality Assurance Testing (QAT): The quality assurance test is done to ensure that the company is providing the best resources in the development of the product. There are standardized procedures that the organization uses to test out the product in the quality benchmark. One thing to keep in mind is that QAT doesn’t involve the actual testing of the developed product.
- System Integration Testing (SAT): System integration testing is performed to verify the interactions between the different modules of a product. It covers all the high and low-level software requirements which the client specifies. In addition, the integration testing also verifies the system’s coexistence with other applications. A tester uses the integrated hardware and the software environment to demonstrate how the product will perform with the optimal hardware resources.
- User Acceptance Testing (UAT): This testing is performed by the end-user or, in many cases, by the client before the product goes into the production phase. UAT is done after QAT and SAT as it will validate the end-to-end business flow of the application. The UAT is carried out with a production-like data setup carried out in a separate testing environment. It is quite similar to black-box testing where more than two end-users are involved to see if the product can provide the expected results.
Before the testing of the product begins, the project team comes with a testing plan created explicitly for the product. The test plan will include several testing methodologies that the developers will use during the testing phase. Along with this, resources for testing, how the different software features will be tested, and who should be testers.
Moreover, the test scripts are used, which are the instructions that each tester needs to use. The test scripts are made to ensure consistency between the various testing cycles of the software.
This is the phase where the work and information gathered from the design, development, and testing team is combined into a single application, which is shared with the client and the consumers of the software service. When a project reaches this phase, it means the software has been successfully developed, and the test results were satisfactory.
Thus, the project is ready to go live, but there are many deployment processes that the project team needs to follow to make sure that both the technology and the design used in the product get deployed correctly. The deployment process consists of deployment preparation and procedures, transferring the ownership to the client, and closing the deployment phase.
The product has been delivered to the client successfully, and the client’s customers are now using the product. Once people start using the product, they will undoubtedly encounter some errors. This is quite common, and it happens to almost every developed product. It doesn’t matter if it’s an AAA video game title, Apple’s new macOS, or a recent Windows update by Microsoft. The development team needs to look at those errors and provide solutions that could be deployed in patches or updates depending on the size of the error.
These were the seven different SDLC phases that are present in each SDLC model. Each step has its importance, and in some SDLC models, they overlap each other. While in some SDLC models, each phase works separately, and only after one stage of the SDLC is complete, the project moves to the other stages. For example, an organization that creates software for their clients needs to use SDLC to complete the projects more efficiently and in the given time frame with ease.