Traditionally, software maintenance takes only technical information into account to evolve legacy systems. However, business knowledge, which could help to improve the comprehension of legacy systems, is rarely recovered. Probably, that knowledge is not considered due to the fact that business knowledge recovery is a problem with a non trivial solution. This paper contributes to the solution of this problem through the use of a set of patterns and the implementation through QVT transformations, which takes KDM (Knowledge Discovery Metamodel) models concerning the system and obtains BPMN (Business Processes Model and Notation) models to represent the embedded business knowledge. A case study reports that the transformation obtains cohesive and loosely-coupling business processes diagrams; and it is scalable to large systems. As a consequence, the business processes recovery can enhance the maintenance since they provide the business concept location in legacy systems, among other impro...