A QA Manager’s Guide to Software Testing Methodologies

Within the competitive software industry, there can be no space for mistakes. Software testing methodologies are pivotal for the software development life cycle, giving a sense of direction of how tests should be conducted. Let me tell give you an example –

It was during the cold January of 2016 that Google Nest Smart Thermostat had one of the epic software failures – talk about being unlucky!

A software update caused the entire application to glitch, causing the batteries to drain out and leaving its consumers in a freezing cold situation, literally and metaphorically. The company was forced to respond immediately after an outcry by thousands of its users in America by releasing a new version that fixed the bug causing the issue.

Software Testing Methodologies vs. Types of Software Testing

Let’s start with the differences between testing methodologies and types of software testing.

Software Testing Methodology

The methodology is a testing strategy for simultaneously developing and testing a software application to meet the clients’ requirements. The testing approach defines the project management, organizational structure, and software testing methods.

Types of Software Testing

The different types of software testing are the technical side of the testing process that ensures the application is performing as intended. It is categorized into functional testing and non-functional testing.

Five Popular Software Testing Methodologies

While there are several models for testing, the list below emphasizes some of the popular and most used ones.

1. Waterfall Methodology

Amongst the rigid software testing methodologies, the waterfall methodology is one of those models where the focus is on a development process that follows a vertical path.

Testing Approach
The sequential path of a waterfall methodology has defined steps of order –
The ‘requirements’ phase ensures all the necessary requirements like testing objectives, organizational planning, draft documents, and the testing strategy is defined and fixed.

Advantages

• It is a step-by-step laid out test strategy.
• The methodology can be used to easily to plan and manage project requirements.
• It is inexpensive and provides faster delivery of projects.

Disadvantages

• Each step in the methodology is predefined and cannot be skipped.
• It can’t absorb unplanned iterations.
• Testing is pushed down for later in the list.
• Even a slight iteration to the project plan can be expensive.

Use Cases

• Customer Relationship Management systems
• Human Resource Management systems
• Supply Chain Management systems
• Inventory Management systems
• Point of Sale systems

2. Agile Methodology
The agile testing methodology is based on the idea of iterative development, where development progress is made in rapid incremental cycles, also known as sprints.

Testing Approach
The origin of the agile methodology was meant to break away from the rigid and model of development and testing that does not give space for iterations. This is one of the reasons that the testing team prefers using this approach for dynamic applications to accommodate constant feedback from stakeholders.

Advantages

• Complex application processes can be easily managed, changed, and tested.
• Incremental tests minimize the cost and risks associated with numerous changes.
• The constant communication between developers and clients determines the progress of the software application.
• The focus of the methodology is on testing rather than planning.

Disadvantages

• Increased to and fro with clients may lead to longer delivery times.
• Less priority on planning may lead to documentation inefficiencies.
• Constant changes make maintenance difficult.

Use Cases

• Defining the testing scope of an application.
• New functionalities in an application
• Load and performance testing

3. Iterative Development Methodology
The methodology works by breaking down a large project into smaller components, where each component goes through a series of testing cycles.

Testing Approach
The iterative development model follows a cyclical pattern for testing smaller components of a large project. Each iteration cycle is identical to a complete development cycle and consists of planning, design, testing, and evaluation phases.

Advantages

• Smaller iterations for complex software applications decrease the time and cost of development.
• Feedbacks of the iterative cycles are immediately available.
• With each iteration cycle, the errors and bugs get removed at the initial development stages.
• The model allows more flexibility and focuses on the design instead of documentation.

Disadvantages

• Communication overheads might increase significantly after each feedback. iteration
• The iteration cycle is rigid and cannot be overlapped.
• Unpredictable feedback might delay the delivery of the final product.
• A low priority on planning might lead to unforeseen circumstances.
• User engagement is necessary for identifying risks.

Use Cases

• Gaming applications
• Streaming applications
• SaaS applications
• Prototype testing

4. Verification and Validation Methodology
The V-methodology is considered an extension of the waterfall model, used for small projects with defined software requirements. It follows a ‘V-shaped’ model that is categorized into coding, verification, and validation.

Testing Approach
The ‘V-model’ stands apart from the waterfall model in terms of parallel testing procedures conducted at each development stage. The verification process ensures that the product is developed correctly, while the validation process ensures that it’s the right product as per requirements.

Advantages

• Testing/validation at each stage allows the identification of errors early in the development cycle.
• It’s a cost and time-effective testing model.
• The rigidity makes it ideal for small projects.
• Each stage of the validation and verification has well-defined objectives.

Disadvantages

• There is no inherent ability to respond to errors during the testing process.
• There is no defined solution for eliminating the software defect.
• The model is not suitable for large projects with higher chances of changes.
• It cannot handle concurrent events.
• There is no going back after a module has entered the testing phase.

Use Cases

• Medical devices and software applications.
• Government applications and software projects.
• Defense projects and applications.
• Commercial applications.

5. Rapid Action Development Methodology
The testing model is a form of an incremental methodology that originated out of the agile software development system. The cornerstone of RAD is prototyping while parallelly developing components for the software, therefore, focusing more on testing rather than planning and documentation.

Testing Approach
The RAD methodology consists of five phases through which the system components are developed and tested simultaneously. Each of these phases is time-bound and must be done promptly, making it suitable for projects with a tight deadline.

Advantages

• Simultaneous designing and reusability of the prototypes reduce development and testing time.
• The time-box approach at each incremental stage reduces the overall risks in the software project.
• Feedback cycles increase customer satisfaction.
• The progress is measurable and data-driven.
• Changes can be easily accommodated.

Disadvantages

• The methodology is challenging to use with legacy systems.
• Continuous client feedback and modifications can delay the deployment.
• There is a high dependency on technical skills and resources.
• Automation testing, tools, and code generation lead to higher costs.

Use Cases

• Enhancing application graphic user interface.
• Application prototypes (Wireframe, Design, and Clickable prototype)
• System modularization.

Conclusion

Testing has always been an integral part of the software development life cycle. It enhances application performance, improves security, and provides quality assurance. But it is not as simple as utilizing a testing tool and running the application to look for errors.

Check out the original article to read more about Software Testing Methodologies.