In some cases there is a need to compare similarities between different process models. For example, given two organizations that offer products or ser- vices with similarities, we would like to know how much they differ from each other. This paper aims at defining a method to create a process reference model, which can be adapted to heterogeneous organizations. In order to construct this, we propose a method using BPMN language and based on the value chain ap- proach. This process reference model issued from heterogeneous structures could enable managers to achieve a more comprehensive and unified vision of their organizations, and promote a coherent monitoring of activities. This work pre- sents a unified method of communication between managers and organizations as well as throughout the structures comprising the organization. It provides a basis to establish an alignment of different structures in term of goals and business process following two axes.