This presentation introduces orthogonal array testing (OATS), which is a systematic statistical method for testing all pair-wise interactions using fewer test cases. It discusses the terminology, advantages, and disadvantages of OATS. Specifically, OATS allows testing all combinations of variables more efficiently than exhaustive testing. It guarantees coverage of all pair-wise combinations using an orthogonal array with far fewer runs than would be required for conventional testing. However, it may miss some higher-order combinations and can be difficult to construct.