Non Functional Testing

Nonfunctional testing covers load testing, usability testing, performance testing, and other non-functional testing methods. It assesses the non-functional characteristics and responsiveness of a software product or system.

Types of Nonfunctional Testing

These types of nonfunctional testing are used by software quality assurance teams:

• Performance testing

• Usability testing

• Stress testing

• Load testing

• Maintenance or maintainability testing

• Reliability testing

• Portability testing

They evaluate the effectiveness of a system component or software application. Essentially, you are assessing the quality of the software product's characteristics and sub-characteristics, which means you are examining the software's attributes for quality.

Quality Attributes of Nonfunctional Testing

These are attributes or characteristics and sub-characteristics relevant to nonfunctional testing:

• Functional: Assessing the software's accuracy, appropriateness, security, interoperability with other systems and devices, and compliance, which are the same characteristics considered in functional testing.

• Reliability: Evaluating the software's robustness, responsiveness to failure, recoverability from errors and failures, and compliance.

• Usability: Focuses on the software easy of use, understandability, operability, learnability, attractiveness, and compliance.

• Efficiency: Assesses the timeliness of the software's behavior or performance, its impact on productivity, and compliance.

• Maintainability: This aspect of testing involves monitoring changes, analyzing stability, and ensuring compliance of the software.

• Portability: Checking the software's adaptability to changes, software installations, co-existence with other applications and devices, and compliance.

It is beneficial to conduct nonfunctional testing at all testing phases, although it is costly and time-consuming, as the benefits outweigh the challenges.

Reference: Black, R., Van Veenendaal, E., & Graham, D. (2012) (3rd Edition). Foundations of Software Testing. ISTQB Certification. Delhi, India. Cengage Learning.