Evan et al,

PMFJI here, but I battle with this. How about an RI/business rule like this?

"the line item must have an RI link to a parent Purchase Order IF it is a line item with a 'PO' billing code, but must have no link if it is a line item with a 'Time' billing code"

That rule has components of both BR and RI - so - where does it go?

Ken

>John you asked me to give you an example that does not apply to the business domain (not an RI example). The example below applies to every dataset regardless of business domain.
>
>>This is not an RI issue, it's more of a constraint issue. I do agree that a lot of the constraints can be implemented in the business tier (especially to minimize roundtrips) but that's a separate issue.
>>
>>>>Can you give me an example of data that only pertains to itself and not to the business domain? IMHO, data is just an outcome or representation of, as you say "carrying out the business domain" and is pretty synonymous with each other.
>>>
>>>Sure.
>>>
>>>Example: Birthdate must be less than or equal to date of death. This is true for every data set regardless of the business domain.