Orthogonal Array Testing
Introduction
Orthogonal Array Testing (OAT) is a systematic, statistical way of testing multi-parameter systems. It is a black-box testing method that is used in the field of software testing. OAT is based on the concept of orthogonal arrays, which originates from the field of design of experiments. The method allows for efficient and effective testing of software systems with multiple parameters.
Orthogonal Arrays
Orthogonal arrays are mathematical structures that provide a set of well-balanced (uniformly distributed) scenarios. They are used in OAT to ensure that all possible combinations of parameters are tested. The concept of orthogonal arrays was introduced by Indian mathematician C. R. Rao in the 1940s.
An orthogonal array is defined by the parameters L, k, v, t, where L is the number of runs (test cases), k is the number of factors (parameters), v is the number of levels (values each parameter can take), and t is the strength (the size of the interaction).
Application in Software Testing
In software testing, OAT is used to reduce the number of test cases by selecting a subset that covers all interactions of 't' parameters. This is particularly useful in the testing of complex systems where exhaustive testing is not feasible due to the large number of parameters and their possible interactions.
The application of OAT in software testing involves the following steps:
1. Identification of parameters and their possible values. 2. Selection of an appropriate orthogonal array. 3. Mapping of the array to the test cases. 4. Execution of the test cases. 5. Analysis of the test results.
Advantages of Orthogonal Array Testing
The main advantage of OAT is its efficiency. It allows for the testing of all combinations of parameters with a minimum number of test cases. This reduces the time and resources required for testing.
Another advantage of OAT is its effectiveness. It ensures that all interactions of parameters are tested, which increases the likelihood of detecting defects.
Limitations of Orthogonal Array Testing
Despite its advantages, OAT has some limitations. It assumes that defects are caused by interactions of 't' or fewer parameters. If a defect is caused by an interaction of more than 't' parameters, it may not be detected.
Another limitation of OAT is the difficulty in selecting an appropriate orthogonal array. The selection of an array depends on the number of parameters and their possible values, and there may not be an array that exactly matches the requirements.
Conclusion
Orthogonal Array Testing is a powerful tool in the field of software testing. It provides a systematic and efficient way of testing multi-parameter systems. Despite its limitations, it is widely used in the testing of complex systems where exhaustive testing is not feasible.
