For businesses, delivering quality products and services to the customers is their primary goal. But, they may face many issues in the software development process–from the requirement gathering phase to releasing the software in production. If you want to develop high-quality software in less time, it is important for you to understand the following:
- Software development life cycle (SDLC) and its phases.
- SDLC models that are suitable for your project.
- Importance of quality assurance and quality control.
Software Development Life Cycle (SDLC)
SDLC is a framework that defines the phases involved in the software development process. These phases define how to build, design, develop, and maintain the software within the organization.
Phases of SDLC
1. Requirement analysis
Requirement analysis is the first and most essential step of the software development process. In this phase, experienced software engineers aim to:
- Analyze the software requirements from the user’s perspective.
- Gather software requirements.
- Discuss each requirement in detail to ensure everyone on the team understands the scope of the project.
- Create a Software Requirement Specification (SRS) document that describes how the software will perform when embedded with hardware.
- Find the solution to the issues that clients are facing.
- Plan for resources, costs, time, etc.
During the design phase, technical architects and developers unite to create software architecture and system design.
The workflow in the design phase:
- Project team discusses technical details of the design with the stakeholders.
- Variety of parameters (including required technologies, risks, team’s capability, project constraints, and budget) are reviewed to select the best approach for the software.
- After selecting the architecture, Design Specification Document (DSD) is created that contains the details about the software product, such as the behavior of components, user flows, database communication, front-end design, etc.
After analysis and design phases, the next phase in SDLC is the development phase. In this phase, the developer team starts coding to meet the required specifications discussed in the previous phases.
Work responsibilities of a development team:
- Front-end developers create GUI and user interfaces according to the procedures and guidelines defined by the organization to sync with back-end processes.
- Database administrator creates the database.
- Developers review each other’s code.
In the testing phase, experienced testing engineers will do the following:
- Create test scripts to execute the code to find inconsistencies and errors in it.
- Verify the system to check if it is in accordance with the SRS document.
- Testers inform the developers after the defects have been identified. Then, developers fix the bugs and send the code modules again to the testers for verification.
After fixing all the defects, the software is ready for shipping.
5. Deployment and maintenance
After the software has been completely tested and free from all the defects and issues, the team deploys the software to production so that customers can use it.
After that, the maintenance team (comprised of testers and developers) comes into the picture. They fix all the post-production issues found by the customers.
The testing process goes hand-in-hand with every phase of SDLC. Let’s look into more details:
Testing engineers analyze and review the SRS document to determine the testing strategy and methodologies to be followed during the development process.
The testing team identifies the testing points and plans testing strategy accordingly.
Testing engineers create test scenarios to validate the quality of the software.
Based on test cases or scenarios, the testing team starts integration testing and regression testing to find defects in the code.
The testing team performs acceptance testing to evaluate if the software is acceptable for delivery.
Basic SDLC models
SDLC models are used to regulate the project-based work among IT professionals within an organization. The basic type of SDLC models are:
1. Waterfall model
The waterfall model follows a sequential order in the software development process. It means the project team moves to the next phase of SDLC only after the previous phase has been completed successfully.
Some key points about the waterfall model:
- While approaching the waterfall model, you have to be clear about all the product requirements in the ‘requirement analysis’ phase only, because once the project development starts, changing any requirements will affect the whole process of software development.
- In this model, testing phases comes after the ‘design’ phase.
- It does not require customer interaction in the development and testing process.
2. Agile model
An agile approach promotes sustainable development. In this, the client is involved throughout the project, including planning and reviewing the addition of new modules or features in the software. In this model, a software product is divided into small parts, and the development and testing process are carried concurrently, in a continuous iteration.
Some key points about Agile:
- It speeds up the software delivery process.
- Using this model, the team has a better understanding of the client requirements.
- Unlike the waterfall model, the agile model accepts the change of requirements, no matter how late or early these changes are included in the project.
Which SDLC model is best for you?
- The waterfall model is suitable for small projects where it is easy to gather the product requirements, whereas an agile model is suitable for larger projects where clients are involved during every phase of the software development process.
- With the validation of risk agreement at the beginning of the process, the waterfall model reduces risk in fixed-price contracts, whereas the agile model works well with non-fixed funding for your project.
Quality assurance (QA) and quality control (QC) in the software development process
Quality assurance and quality control are essential components in software development. But some professionals fail to distinguish between QA and QC as they both sound similar and interdependent. In some cases, this kind of ambiguity may affect the software delivery process because the organization does not have separate resources to hire QA and QC engineers. This, in turn, results in assigning the job responsibilities of QC to the QA engineers and vice-versa. To understand the QA and QC, here are a few key points:
Quality assurance in SDLC is used to prevent defects in software deliverables. Its process starts at the beginning of the software development process to understand business and technical requirements, ensuring the quality of the product.
Quality control ensures that the software deliverables are defect free and in an acceptable state (by customer standards). It focuses on planning, documenting, and finalizing the guidelines required to maintain the quality product.
How are QA and QC interdependent?
- QC receives input from the QA process.
- Then, it gives feedback to the QA process.
- On the basis of feedback, QA will validate the operational process.
For example, if there is any defect in the program execution, it will be sent as feedback to the QA team. Then, the QA team will investigate the cause of defects and identify the preventive measures that need to be taken. Then, the QC team implements the aspects identified by the QA team (such as running test cases, generating bug-reports, etc.) to correct the defect.
Difference between QA and QC
To understand the difference between these two processes, look at the comparison table below:
Quality Assurance (QA)
- QA focuses on identifying, analyzing, and preventing the cause of defects in the product.
2. It is the process of managing product quality, for example through a quality audit.
Quality Control (QC)
1. QC focuses on finding the defects and errors in the product.
2. It is the process of verifying the product quality, for example through testing and inspection.