## 7 A Proof of Concept on a Real Scenario  
An additional evaluation has been carried out to verify the usability of the proposal in a real scenario. The authors have been working during recent years in several projects dedicated to issues related to traceability in a broad sense. In the due course of this researching activities, the authors have tackled the problems derived from hazardous medicines in the health field [48]. This leads us to propose extensions to the BPMN notation for its application in Hazard Analysis and Critical Control Points (HACCP) [26] scenarios or to the identification of gaps and needs for standardization of hospital protocols of a dangerous nature [49], among others. Given this trajectory, the proof of concept for this proposal was focused on the field of the management of hazardous drugs (HDs). HD are those drugs whose handling poses a danger to people (carcinogenicity, teratogenicity, reproductive toxicity, low dose organ toxicity, genotoxicity, among others) [50]. In [49], the authors focus their efforts on the identification of the stages that make up the life cycle of the HDs and, for each of them, certain action protocols are defined. Subsequently, in [51], an assessment is made of the advantages of applying the BPMN extension proposed in [26] for this domain of interest. In this work, 47 experts in the domain evaluated the benefits of the proposal. An adaptation of a BPMN model presented in this last work was selected to check the usability of the simplification proposal. The chosen BPMN model can be seen in Figure 13.  
This model summarizes the tasks carried out for the administration of an HD. During this stage, two roles are involved: Nurse (N) and Auxiliary Nurse (AN). There are also four possible ways to administer the HD and they are shown in Table 4.  
By collecting the opinions of sanitary experts at different levels about the processes related to the management of dangerous medicines, some existing limitations arose. The models currently in use tend to include all the actions carried out by different health profiles. In this way, it is possible, in a single diagram, to represent several perspectives. However, this introduces a drawback: each of the individual roles involved in the process may have too much information (some of the data can be considered as noise). In this way, the interpretation of the model is sometimes more complicated than necessary and could lead to errors. For example, a person with the AN role may not be interested in knowing the sequence of tasks that another person with the N role must perform. Therefore, it is preferable for the person with the AN role to have a model simplified that represents only those tasks required for his/her role. Following, two particular scenarios that show this idea are presented. As a first example, let's assume that a person with the AN role wishes to visualise only the activities involving his/her participation. Besides, he/she is only interested in those tasks involving ophthalmic administration, as this person only is capable of performing this procedure. In this line, the goal of simplification would be to produce a new simpler model that contains only the relevant information for this context. Applying the proposed two-phase algorithm, it would be possible to obtain the BPMN models shown in Figure 14a,b (output of stages 1 and 2, respectively). The model in Figure 14b represents in a much more synthetic way the relevant information for the AN role. For the second example, let's consider the case of a person also involved in the administration of the HD under the role N that wants to check the tasks that must perform. In this case, the list of activities removed in the first stage is different from the first example. The new resulting models generated for this new context are shown in Figure 15a,b.