Infinite is a common strategy in manufacturing, otherwise the delivery date would never be hit. This is nothing to do with software per se, it is how a production plan defines its scheduling. In infinite the business gets the ability to juggle and flex in a moving environment. Only environments which are static demand or constant machines would use finite, but only then in a borrleneck situation. Environments with changing requirements and deadlines would use infinite and would be replanned.
Whilst there maybe an absolute limit and therefore a finite capacity - this is not necessarily the way a business plans.
If it is infinite the capcity of the work centre can be overloaded, so you can look at the work centre inquiries and see red crosses. This will mean the plan will go back from the required date giving all items are in stock based solely on the routing times and let you manage by exception capacity issues.
With finite capacity the system will look for availability of capacity, this can lead to large gaps, so you can start operation 10 today and finish it today at 14.00 but operation 20 cannot start for three weeks because another works order has the resource, so operation 20 gets scheduled to start in three weeks time. Basically you cannot overbook time in the work centre, which pushes the delivery date out and out.
The finite approach also means you are constantly juggling orders in AX based upon which is “really” needed first, whether it is stock or customer AX will plan as each comes in and then businesses spend hours juggling the plan.
Basically create a work centre that has an hours capacity a day - then load a works order that needs this resource for 10 hours. Then load another order and look at the scheduling (assume finite scheduling). Then set the work centre to infinite and replan both orders and see what happens.
I would not, this is an indication the work centre/group has insufficient capcity, so analyse the requirements, the data and where you need to reschedule and let someone know something will be late.