Language Migration is a highly risky and complex process. Many authors have provided different ways to tackle down the problem, but it still not completely resolved, even-more it is considered almost impossible on many circumstances. Despite the approaches and solutions available, no work has been done on measuring the risks and complexity of a migration process based on the technological gap. In this article we contribute a first iteration on Language Migration complexity metrics, we apply and interpret metrics on an industrial project. We end the article with a discussion and proposing future works.