As you can see, some managed objects are typed, while others are categorized. Actually, typed objects are also indirectly categorized (in addition to being typed) because all Types are themselves in Categories, but it’s easier to just say “typed objects”, and also saying “typed and categorized objects” leads to ambiguity about whether you are also talking about the objects that are categorized but not typed.
Typed objects are those for which there is a “type object” that describes many of the attributes of the typed object.
For example, an Equipment Type object describes many key attributes that all equipment objects of that type share, such as physical dimensions, number of ports, and model number.
One easy way to think of a type object is that it contains much the same information that a product brochure or data sheet might have.
Using an Equipment Type object to create an equipment object is the IRM equivalent of calling a vendor to say “I want one of those Cisco 890 products” while looking over the data sheet for the Cisco 890.
It is important not to confuse these type objects with their corresponding instance objects (we use the term instance object when we want to make sure there is no confusion with the corresponding type object).
For example:
You can use the following to relate the Category, Type and Instances definitions in IRM to real world objects:
The Category of an Equipment Type in the Object Model could relate to a section within a Vendors Product Catalog (e.g. Network Switches, Edge Routers, Copper Patch Panels, etc).
The Equipment Type relates to a product listed in the section of the Vendors Product Catalog (e.g. Cisco 3948, Cisco 11000, 48 Port Cat6 2U Modular Patch Panel).
An Equipment Instance is what was received by the customer after placing an order for an Equipment Type from the Vendors Product catalog.
