Testing is one of the most critical processes of the Software Development Lifecycle (SDLC). It helps companies to perform a comprehensive assessment of software and ensure that their product fulfills the client’s needs.

The testing phases of the software development lifecycle help companies to identify all the bugs and errors in the software before the implementation phase begins. If software bugs are not resolved before deployment, they can adversely affect the client’s business.

Besides that, trying to resolve these issues at a later stage can incur substantial costs. The more you delay the detection of these issues, the greater the cost you are likely to face.

There are several ways to perform testing in the software development lifecycle. The techniques used for testing can vary depending on the software development model, the stage of the process, and the objectives of the testing procedure.

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types of testing in sdlc

Software Development Lifecycle (SDLC)

The Software Development Lifecycle or SDLC is a methodology used for developing software. The process comprises a series of steps needed for building, maintaining, altering, replacing or enhancing the components of software.

SDLC serves as a pipeline for implementing software projects in a structured manner. As a result, companies have a procedure they can use for improving software quality and optimizing the overall development process.

testing phase in sdlc

Testing Phases in SDLC

The SDLC is a continuous process, and thus, consists of several phases. Each of these phases is critical for meeting the requirements of clients and achieving the goals of the project. The following are some of the integral phases of the Software Development Life Cycle.

Requirement Analysis and Planning

Project planning and requirements are the most fundamental phases of the SDLC. Without understanding the initial requirements, no software team can develop a solution that gives value to clients.

Usually, the senior members in a project team are responsible for carrying out requirement analysis. The team constantly takes input from the client during this procedure. They also have to consider the feedback of the sales department, and consult experts in the industry along with market surveys.

After carrying out in-depth research about the client’s requirements, the management uses this information to determine the approach they will take for the project. The team needs to conduct a feasibility study and determine whether or not the project is feasible, both economically and operationally. Besides that, the team needs to see if the current team has the technical capability to carry out the given task.

At this stage, the team also needs to plan the scope for quality assurance and perform risk evaluation of the project. At the end of this phase, the team has to define the technical approach they will take to implement the project successfully.

Validating Requirements

Once the team has completed the requirement analysis process, it is time to gather all the requirements for the project in a document. Furthermore, they need the client to see all the requirements the team has gathered and validated. This step is needed before the development team starts working on the project.

For this purpose, the team prepares a document known as SRS (Software Requirement Specification). The document lists down all the functional and non-functional requirements of the project that the team has to develop and design during the project lifecycle. The SRS document will serve as a point of reference for the next phase.

Designing the Product Architecture

Product architects use the SRS document to design an optimized architecture for the product. These professionals base their design on the requirements enlisted in the SRS. In most cases, they use more than one approach to design product architecture.

Once they complete the product architecture, they will save it in the Design Document Specification (DDS). This document may contain diagrams such as the Entity-Relationship Diagram (ERD) for data modeling or Data Flow Diagram (DFD). The DDS document requires the approval of all stakeholders before being passed.

Software Development Phase

In the development phase, the developers start working on the actual project. They develop the code from scratch using the design specifications given in the DDS. Depending on the SDLC model your company uses, the way you deliver components of the software may differ.

However, programmers need to follow the best practices while coding components of the software. Clean and efficient code can have a great impact on the performance of the software. Therefore, it is important for programmers to write code in a detailed and organized manner.

With that said, the language used for constructing the code for the software can differ according to the type of software being developed, the objectives of the software and the environment it will work in.

Testing Phase in SDLC

In most cases, testing remains a consistent part of the project throughout the SDLC. Therefore, it is always involved in SDLC in some way or another, regardless of which phase you are currently in.

The main goal of the testing procedures is to report, monitor, resolve and retest software components until they reach the quality standards defined in the initial SRS. Many teams use documents such as RTM to trace the main requirements of the project and see how they affect each other.

Deployment and UAT Importance

Once you have tested the product and ensured that the product meets the standards defined in the SRS, it is time to deploy the product where the customers can access it. Usually, software companies release their products formally in the market.

Other times, product deployment can extend over several phases based on the business strategy of the company. Many companies utilize methods such as User Acceptance Testing to get feedback from the expected users of the software. As a result, they get the chance to test the software directly in a real-world environment.

Furthermore, the feedback given by the users allows them to know what exactly to change in the product needs for further improvements. It can also help them to reshape the product to best fit the requirements of a particular market segment.


While a few projects end after the deployment of the software, the majority of software products require maintenance services from the software vendor after its completion.

sdlc models in software testing

Role of Testing in Software Development

We cannot downplay the role of testing in software development. The procedure can help software teams in validating the functional and non-functional features and requirements of projects.

It’s possible for new features to influence the functionalities of previously deployed features. Testing can help you to catch these problems before they interfere with the end product.

Furthermore, if you apply testing in the early stages of the project, it is much easier to detect hidden errors. Therefore, the cost of resolving these bugs is minimal when compared to the later stages. Since the testing procedure gets rid of the critical bugs of the software, it makes your end product superior compared to that of your competitors.

The quality of the product speaks for itself and users can recognize the difference in quality and experience. Not only can testing invoke greater engagement from users, but it can also minimize the overall development and maintenance costs of the project.

sdlc in software testing

Models of Software Testing in SDLC

software team can choose any of many software development life cycle models during their projects. Each model contains a series of unique steps that the team has to follow to complete the project.

Waterfall Model

The Waterfall development model follows a linearly sequential flow. In this methodology, the requirement analysis, designing, development, integration, testing, and deployment phases are clearly defined in separate phases and none of these phases overlap each other.

The project workflow only proceeds forward and teams cannot begin one phase before the previous phase ends. However, once a team has passed that phase, they cannot go back to the previous phase.

It is one of the earliest models derived by software engineers but is rarely used today. One of the major uses of this model is in projects that don’t have changing requirements and require extensive documentation.

V-Shaped Model

The V-shaped is similar to the waterfall model in many ways. However, one significant change in how the testing of software components is planned. Furthermore, the project does not follow a downward trend towards completion.

Instead, the process turns upwards after the development phase and testers use the test plans created earlier to evaluate specific components of the product. The shift starting from the development phase allows forming a typical V shape.

Prototyping Model

As the name suggests, the model promotes the concept of creating bare-bone versions of software applications that serve as the prototype for the application. It helps to visualize components of the software and used in projects where the user experience and application design is a critical aspect of the project.

The approach reduces the length of a project that follows the waterfall of similar approaches and makes it less time-consuming. Once the final prototype of the project is completed, the requirements of the project are frozen.

Iterative and Incremental Model

The iterative and incremental model is designed to overcome the weaknesses of linear models like a waterfall. After the planning in the beginning, the project is approached with a cycle of iterations and where developers code software components in small iterations and deliver them incrementally. In these models waterfall methodologies are implemented at the granular level.

Agile Model

The Agile model is centered around the iterative and incremental approach and cross-functional teams work in collaboration to meet the requirements of their clients. These projects require constant engagement with clients and are able to handle changing requirements more effectively than other models. Less time is spent in requirement analysis and more emphasis is given on practical feedback from clients after using developed software components.

need of software testing

Types of Testing in SDLC

Testing phases are some of the most important components of the Software Development Life Cycle. These processes have to be executed in a methodical approach to ensure that all requirements are met. Software testers usually break down software testing in four main phases, which are System Testing, Integration Testing, Acceptance Testing, and Unit Testing.

Unit Testing

Unit testing is performed on smaller components of the software, which testers can term as a single unit. These units can be as small as individual functions, code components and even classes, or large as single features of the software.

Usually, it is the smallest testable component of the software that the testers can compile load and execute. Unit testing ensures that each unit of the software is functioning as it should.

Integration Testing

In integration testing, testers combine different software modules at once test these modules collectively. This kind of testing ensures that the collective system follows the correct data flow. These tests are necessary to make sure that the integrated system is prepared for system testing.

System Testing

System testing is the procedure where collective systems in integrated testing are combined further into a single integrated system. Here testers evaluate the functional requirements of the project once more and also see whether the system follows compliance according to the given requirements.

Besides that, testers can also evaluate how overall components interact with each other. Therefore, they can perform specific testing procedures such as performance, load, reliability and security testing on the integrated system.

User Acceptance Testing

In user acceptance testing, customers use components of the software to see if it meets their requirements. They can ask the development team to make further enhancements in the product if it is needed. This final interaction with end-users and stakeholders can ensure that all the agreed-upon requirements are a part of the product.

importance of software testing

Software Testing in SDLC by PFLB

Simply identifying errors in the last stage of an SDLC is not an efficient practice anymore. There are various other daily activities a firm has to focus on. Devoting too much of your precious time to testing and fixing bugs can hamper efficiency.

PFLB is one of the leading software testing service providers out there. Our company has been providing software-testing services to over 500 companies across all industries, from Finance and Healthcare to Retail and Technology.

An experienced software testing company will carry out all the steps of the SDLC for you and identify all possible bugs in your application. Annual support is also an option. Find out how much your business can save with PFLB?

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