The designer of a database builds a formal model of the application area or universe of discourse (UoD). The model requires a good understanding of the UoD and a means of specifying this understanding in a clear, unambiguous way. object role modeling (ORM) simplifies the design process by using natural language, as well as intuitive diagrams which can be populated with examples, and by examining the information in terms of simple or elementary facts. By expressing the model in terms of natural concepts, like objects and roles, it provides a conceptual approach to modeling.
ORM was developed by Terry Halpin .
Early versions of object role modeling were developed in Europe in the mid-1970s (for example, binary relationship modeling and Nijssen's Information Analysis Method (NIAM)).
Microsoft ORM Visio Tool
Microsoft has an implementation of ORM embedded within the product "Microsoft Visio for Enterprise Architects." With the Visio tool a user can design and build database in fifth normal form.
A user can also reverse engineer one or more databases into natural language and then check their semantic accuracy with ___domain experts. Microsoft chose not to prepare a "how to" manual for ORM. Instead, Microsoft supported ORM experts who wrote the book "Database Modeling with Microsoft Visio for Enterprise Architects." So if you want to use this tool, it will help if you buy this book.
External links
- Object Role Modeling: An Overview (msdn.microsoft.com)
- orm.net
- ormcentral.com
- objectrolemodeling.com
The Dutch successor of NIAM is continuously researched and developed and is called FCO-IM. The case tool of choice implementing this is called Casetalk. FCO-IM has some advantages for it considers only facts.
References
"Information Modeling and Relational Databases" written by Terry Halpin.