There are two major pitfalls in the development of extensions to the BPMN 2.0 metamodel.
First, there is a lack of methodological guides considering the extensibility approach supported by the extension mechanism of the language.
Second, BPMN does not provide any graphical notation for the representation of extensions.
This work proposes a method based on Model-Driven Architecture for the development of extensions to the BPMN 2.0 metamodel. It enables the conceptual modeling of extensions by using UML, their graphical representation in terms of the BPMN extension mechanism, and their transformation into XML Schema documents that can be processed by BPMN tools. A tool supporting the proposed method is also presented.