Modeling is the art of describing objects, rules and roles and relating them in processes with a descriptive language from a particular viewpoint.
Note: When I say «art», I mean art. As the writing of code for a developer is a creative process and influencing customers in buying a product requires highly creative techniques for a sales person, the same is true for modeling.
When the inventory for a material falls below a certain level, the inventory manager is alerted by the system to restock, but not more than a certain quantity. Material would be the business object, the inventory manager and the system are the business role, below a certain level and not more than a certain quantity are business rules. All of them are tied together in a business process. The machine alerts the inventory manager based on the rule that there must always be a certain quantity of this specific material in stock, and sets the status for sufficient inventory to red. The inventory manager than either does make an order or does not.
When talking about modeling, multiple elements have to be considered in the modeling process. These are: