Abstract: A method for versioning business process models within BPM systems is provided. For this method, each version of a business process model is allowed to have an associated label. The label is defined by a user of a process modeler within a BPM system. The user can also choose the active version of each business process model. The business process server (execution engine) of the BPM system creates business process models using the active versions of the business process models. Changes in an active version (i.e., by replacement with a new active version) do not effect existing business process models. These existing business process models continue using the business process models with which they are created. In this way, the versioning method allows business process models to be changed within active BPM systems, without the need for system shutdown.