# TransformingBPMN Processes toSBVR Process Rules with
## 2 Related Work
### Concepts' Definitions, Issues, and Pre-Conditions to Be Considered  
**Definition of a process rule. ** Since the first comprehensive research publications on the business rules subject in the last decade of the XX century [50; 51; 52], there has been a lot of arguing persisting about what business rules actually are or what they should be, etc. We will not go into the extensive discussion over this subject here, but rather introduce the concepts of a behavioral business rule and a process rule, the latter being one of the cornerstones of our model transformation approach presented in this paper. In SBVR, a _behavioral business rule_ indicates something business participants are either obliged to do (an obligation) or prohibited from doing (a prohibition), except where there is some explicit advice of permission given (a permission) [8]. We define a _process rule_ (also known as a process-related rule) as a kind of behavior rule, which explicitly guides and constrains the flow of work itself (i.e., \"... the sequence and timing of activities\" [53]) within a given business domain. In the context of BPMN and SBVR standards, process rules specify the flow of work presented in a BPMN process model in a well-structured set of natural language-based SBVR rules with deontic modalities inherent to the behavioral rules. Next to other kinds of business rules, the process rules have their place in the so-called process-rule continuum as well [13]. **SBVR's capability to represent BPMN processes. ** When deciding on the matters of representing certain things, one must always make sure that the language selected for the task has sufficient expressive power to represent those things properly. In the case of SBVR representing concepts of BPMN, we concluded that SBVR should be extended to fully represent process rules and at the same time preserve the semantics of BPMN processes (especially if the reverse transformation is to be considered). Two extension options were considered. The first option was to extend the SBVR metamodel itself. Such an approach has already been applied by several other research groups to meet their specific requirements [33; 42; 54; 55]. However, altering the metamodel of any widespread modeling standard comes at a cost, for example, tracking and applying changes on a metamodel level each time a new version of a standard is issued, accepting the high risk of closing-in in your own \"sandbox\" because the solution with the altered standard metamodel might not be accepted elsewhere, or limiting the range of tool support due to limited tool capabilities to support extensions on the metamodel level. The second option, which we consider an optimal solution for our approach, is using additional vocabulary describing BPMNconcepts. The peculiarity of SBVR is that SBVR itself is a business vocabulary that is meant to be imported into other vocabularies developed for any business domain. Importing other business vocabularies is a common practice in SBVR. Thus, the developed vocabulary for BPMN would be just another vocabulary to be imported for the process rules development; such an approach would not alter the SBVR metamodel, thus avoiding the \"side-effects\" of the previously described first option. However, it should be noted that the development of relevant SBVR business vocabularies for the specification of process rules is not within the scope of this paper, therefore this aspect will not be elaborated any further. **Linguistic Issues. ** Again, the linguistic aspect of business knowledge should be considered during the specification of SBVR business vocabularies, which is not within the scope of this paper, rather than during the phase of the specification of SBVR process rules. Nevertheless, a general awareness of the potential issues of this kind is a relevant topic in the context of this paper as well; thus, it will be briefly discussed in this subsection.