Changes and Best Practices in Functional Testing Services

Functional testing services play a pivotal role in ensuring that the application under test (AUT) meets specified functional requirements. Over time, these services have seen significant changes and have evolved to include a variety of best practices and tools. This article delves into the advancements and updates in functional testing, highlighting the differences between functional and non-functional testing, the importance of various testing types, and the tools that support these processes.

Overview of Functional Testing

Functional testing is a type of software testing that focuses on the sequential execution of the functions or operations of the software to check how accurately the software performs its intended functions. This ensures that each component and system function as expected with respect to functional requirements.

What is Functional Testing?

Functional testing is about verifying a component or system's functionality in relation to the functional requirements. This involves checking if the software behaves as expected, meets user needs, and fulfills its intended purpose. For instance, if the system requires users to input a specific type of data, such as a 10-digit phone number, the system must accept valid entries while rejecting out-of-range or incorrect inputs.

What is Non-Functional Testing?

Non-functional testing, on the other hand, focuses on the quality attributes of the system, such as performance, scalability, security, and user interface effectiveness. This type of testing is essential to ensure that the system not only functions correctly but also performs well under various conditions.

Functional and System Testing

While functional testing is a specific type of testing, system testing is at a higher level, focusing on the entire system rather than individual components. However, functional and non-functional testing are often applied at the system testing level. Functional testing is part of system testing but is also an integral part of unit testing, integration testing, and acceptance testing.

Functional Test Tools

There are several tools available for functional and system testing, such as UFT (Unified Functional Testing), Selenium, RFT (Requirements Factory Testing), and SilkTest. These tools offer comprehensive support for functional system testing, functional acceptance testing, and even system testing. However, they do not support unit testing or integration testing as extensively.

Functional Testing Best Practices

To ensure that functional testing is effective and efficient, it is essential to follow certain best practices. Here are some key aspects to consider:

Functional Test Checklist

Input Domain Coverage: This involves verifying whether the system accepts valid inputs and prevents invalid ones. For example, a phone number field should only accept 10-digit numeric values. If the user inputs 10 digits, the system should accept it; if the input is less or more than 10 digits, an error message should be displayed. Similarly, if the input is alphanumeric, an error should be shown. Data Attributes: Data is characterized by its type (e.g., numeric, alpha bytes), size (e.g., 10-digit phone number, 4-digit customer ID), and range (e.g., insurance policy premium range from 2000 to 2500). Output Domain Coverage: This involves verifying whether the system provides the correct outputs based on the inputs and processes. For example, if the input is numerical and the operation is addition, the output should be the sum of the inputs. Database Testing: This is a subset of functional testing and involves using SQL commands to communicate with any database. It includes data integrity, manipulations, comparisons, retrieval, and backup operations. Error Handling: Functional testing must verify how the system handles unauthorized or invalid operations. The system must prevent invalid operations and provide meaningful error messages. For instance, if the user enters an incorrect username and password, the system should display an appropriate error message. Order of Functionalities: Verify that the system provides the correct order of functionalities. For example, the correct order for composing an email is to launch the application, log in, compose the email, log out, and then close the application/browser. If the system first prompts for login credentials after launching, it is not following the correct order of functionalities.

Conclusion

Functional testing services have evolved significantly over time, focusing on not just the functionality but also the quality attributes of the system. Understanding the differences between functional and non-functional testing, following best practices, and using appropriate tools are crucial for ensuring that the software meets all specified requirements and performs well in various scenarios.