This paper presents techniques to pinpoint differences between business processes. We say that two processes are different if they are not (completed trace) equivalent. We developed techniques to point out where two processes are different and to explain why they are different. This in contrast to techniques that provide simple true/false answers about whether two processes are equivalent or not. We developed the techniques by first formalizing frequently occurring differences that we discovered in practice and subsequently developing the algorithms that detect these differences. The techniques can be used for various purposes, such as detecting differences between processes in a merger between organizations