Code Based Testing

Software verification and validation is a very challenging task because the reliability/accuracy of the functionalities a software performs is a tough job to measure. There are some approaches to testing, which improve the probability of finding the most critical software operational and performance weaknesses with reasonable investments of time and resources. One such test approach, known as “Usage Based Testing”. Usage-based testing is a technique aimed at testing software from the user’s perspective. In usage-based statistical testing, the software bugs that are detected by users are monitored and eliminated by developers, which improves the reliability of the software. Usage-based statistical testing provides a good way to prioritize and perform selective testing.

Usage-based testing depends on the class of users (e.g., experts, new users, special-purpose users) and it implies a sense of the scope and nature of events that might be encountered because of the users. Usage-based testing is most likely to be used in acceptance testing.

Code Based Testing vs Usage Based Testing:

The principle of structural code-based testing is to have each and every statement in the program executed at least once during the test. Based on the premise that one cannot have confidence in a section of code unless it has been exercised by tests, structural code-based testing attempts to test all reachable elements in the software under the cost and time constraints. The testing process begins by first identifying areas in the program not being exercised by the current set of test cases.

Usage-based testing focuses on detecting faults that cause the most frequent failures. Unlike code-based testing, no prior knowledge of the program is necessary for usage-based testing. In usage-based testing, testers and programmers can be independent of one another. However, the testers are required to understand the requirement specifications and they should be familiar with how the software behaves in response to the particular action.

Code Based Testing has several factors that might make the testing phase slower and those factors can be minimized in Usage-Based Testing:

Generating test cases is expensive – Creating and maintaining a large number of test cases is a time and effort consuming process. Furthermore, it requires skilled and experienced testers to develop great quality test cases.

It requires plenty of human intervention – Even with the wide availability of automation tools for testing like Junit by JAVA, the degree of automation mostly remains at the automated test script level, and generally significant amount of human intervention is required in testing.

It is a lengthy process – testing is an enduring process that doesn’t end even after the product has been shipped, and it is almost impossible to achieve completely code coverage with testing to eliminate all the defects.

Advantages:

• Usage-based testing is based on a user-oriented approach
• Implies a focus on detecting the faults that cause the most frequent failures
• Ensures the failures that will occur most frequently in operational use will be found early in the test cycle
• Keeps testing effort to a minimum
• Testing environment resembles the actual operational environment

Disadvantages:

• Lack of systematic testing
• Low-quality error reports
• Difficult to reproduce the test environment
• Much effort is required to examine reports

In statistical testing, a model is developed to characterize the population of uses of the software, and the model is used to generate a statistically correct sample of all users of the software. A software ‘usage model’ characterizes the population of intended uses of the software in the intended environment. Statistical testing based on a software usage model ensures that the failures that will occur most frequently in operational use will be found early in the testing cycle. The usage model is based on the software specification.