In software testing, two types of tests have been conducted: unit tests to verify individual functionalities and integration tests to verify the combination of multiple functionalities. The definitions of unit/integration are ambiguous, making it difficult to distinguish between them. To the best of our knowledge, there is currently no method for detecting this distinction. If we could identify unit/integration tests and measure them as ordinal values, such as the degree of integration-ness, we could use them to support testing. In this study, aiming to support testing, we will consider a measurement method for unit/integration tests. The key idea is to utilize an inclusion relation, which naturally exists among test cases. As an application of the inclusion relation, we propose a method for ordering failed tests to support debugging. We conducted a mutation analysis to evaluate how much our proposal reduces debugging effort compared to a naive method. The results showed that our proposal was effective in 29.7% of cases and confirmed an average reduction of 20.7% in debugging effort.