http://ofbiz.116.s1.nabble.com/Subscription-functionality-tp4643745p4643790.html
You got one possibilty (the simplest one and most used I guess). A little explanation of the data model is at
> Hello list,
>
> I have gone through link of subscription
>
http://www.amicontech.com/blog/subscriptions-in-ofbiz-and-opentaps/, in
> this link I did not find how subscription expires. I tried to find a
> service which should be called on expiration of subscription but I couldn't
> find. As per the given link we need to customize a service in order to
> serve subscription to the user, so I created a simple java service in order
> to see how it's called. It is called once, at the time of placing an order.
> So it will create subscription in the system now if I set thruDate to
> expire the subscription it expires in the system. Is there any service
> which is called to expire the subscription.
> If anyone has any idea how it works then please let me know.