The idea of keeping your process definitions inside a Knowledge Based Repository (Drools Guvnor) and using tools like the Process Designer oriented to end users allows the collaboration between technical people and business analyst to continously improve the knowledge resources. remember that Drools Guvnor also keeps your models, rules, events definitions, global functions, etc with your processes. So it depends on how many of this metaphors do you want to use in order to define how to create the right collaboration method for you.
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