But, it is really a chapter of a book on implementing ITIL (IT's Infrastructure Library) Configuration Management!

http://www.informit.com/articles/article.aspx?p=1154763

This particular chapter is about figuring out what types of "configuration items" (i.e., IT objects) need to be managed, what instances of those objects need to be populated, and how the properties/attributes of the objects are determined.  These topics are described as "scope", "span" and "granularity". 

Under scope, the article highlights the importance of understanding both things (software programs, computers, etc.) and relationships.  For me, relationships are as important as the objects themselves (maybe more important!) - since they describe dependencies and coordinations between objects that become the critical details behind analyses (think about root-cause analyses!). 

Although the subject of what is modeled may vary (IT items versus online shopping accounts), the discussion is quite good regarding thinking about modeling alternatives ("do I need to model everything?"), and makes some concrete suggestions on how to proceed. For example, book chapter lists the following "criteria ... to determine scope" (determining the concepts that need to be modeled):

• Start simple - start with the things that "can be quickly learned and easily maintained"
• Consider the cost - "what [can you] afford to manage and what [can you] afford to ignore"?
• Score easy victories - "build confidence early"
• Look ahead to value - "look forward to projects your organization is likely to tackle ..., and structure your ... [data] to provide the information that will be needed"
• Reduce your risk (related to the data) - determine how you will gather the data and "how you will manage that data"

The other interesting thing about the book chapter (at least for me) is that it highlights the value of CIM, the Common Information Model from the DMTF (http://www.dmtf.org).  As ex-VP of Technology of the DMTF, that is very cool!  

Andrea