How to develop an object model
To develop an object model firstly identify classes and their associations, as they affect overall problem structure and approach. Then prepare a data dictionary.
i) Recognize associations between objects.
ii) Recognize attributes of objects and links.
iii) Simplify and organise object classes using inheritances. Then you verify which access paths exist for likely queries
iv) Iterate and refine model, and
v) Organize classes into modules.