[Data-modeling] modeling products currently in production

[Michael Masouras]

I 'd like to create a type for some products (specifically speakers  
and other audio products) and one very useful piece of information is  
whether a product is currently in production or has been discontinued.

This might be a valuable piece of info across all products - is there  
a common type I should be using ?

Alternatively, would a boolean property "in_production" work or is  
another approach better?

Michael