Hi arubio.
I am fairly new to vCenter Chargeback Manager (vCCM) so I've been doing a lot of research on my own and I believe I can answer your questions.
What is the use of the "Edit Entity Cost" screen?
The use of "Edit Entity Cost" is that you can assign a pricing model and a cost template(optional) to a specific hierarchy, parts of a hierarchy, or specific entities (I know you know that, but I just want to give a complete explanation).
Why assign a pricing model to an entity in a hierarchy?
The reason you would might want to do this is if you want to charge specific entities in a hierarchy differently than others. Why would you charge some entities differently than others you might say? That would depend on business reasons and how you build your hierarchies. For example: Some companies may only want to charge their development VMs when they are powered on versus charging their production VMs whether they are powered on or not. So in this case you can implement different pricing models that have different billing policies in them.
Why is there a range of dates?
This is because say you implemented a pricing model for a specific entity last month. Today you realized that you want to change how you're going charge that entity. The range of dates lets you go back to last month and implement your new pricing model that you came up with today. Or if you already billed out the charges for the last month then you can implement the new pricing model going forward from today. Also, if you want to charge differently from month to month on that entity then you can set different pricing models for each month.
You are right, when you generate a report you can specify what pricing model to use and pick what time frame you want to generate a report for.
When you generate a report vCCM checks to see if you already have a pricing model assigned to the hierarchy or entity you're reporting on. If you have something assigned already then it will us that pricing model. If you do not have anything assigned, then vCCM will use the pricing model that you chose when generating the report.
The date range for the report lets you choose what exact time frame you want the report to reflect. This goes back to the example that if you had different pricing models put in place on the same entity for different months then the report would generate the cost totals based on the different pricing models over that span of time.
Hope this helped.
