1) It seemed to me that a class was merely a container of N groups. From your example, it seems that group ("chemistry professor") was just a sub-group of a group called ("Professor"). In other words:
Professor | +-- Chemistry Professor I was not aware of other fields in the Class, and this was the reason for the suggestion. Since you can still attach roles to the groups, from the example above "Chemistry Professor" could "inherit" the roles from the "Professor Group" 2) You can use standard many/many relationships for this. I have had limited success with this. -AP_ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of George Mardale Sent: Monday, October 01, 2001 10:06 PM To: Orion-Interest Subject: RE: Design strategy Hello Alex, Thank you for your prompt response. Your suggestions are excellent. You're right, the analysis is not correct. I tried to reduce the problem to a simple example. To avoid complexity, I just limited the relationships to 1..*. Maybe the example is not the best, but I only wanted to know if I could model the "Abstract being" bean in Orion. There are still 2 issues we are unclear about: 1. what are the advantages of dumping entity Class? (Class has specific fields that Group does not have) 2. could you please detail the best way to implement a *-* relationship in Orion? Thanks, George.