This paper presents a collaborative platform that allows a set of judges (evaluators) to form business process (BP) groups based on the relationship of a user's query with the BPs stored in a repository and the relevant results to that query. Queries are expressed as complete BP and are presented to the evaluators in order to allow them to form groups of BP taking into account similarity relationships. Additionally, each evaluator can compare the concordance or discordance of his results with relevance judgments issued by other evaluators; in this way evaluator can collaborate in the global evaluation process or change his evaluations. Results of the evaluation can be used to assess the quality of the results retrieved by an automatic BP similarity tool. The proposed platform was evaluated with a set of 54 users and results are promising.