A time and parts ticket can be combined.
In each group to be used a valid ticket has to be available, in order for the user parts generation is possible.
The user may generate 5 tickets a day for 4 weeks.
When he has generated 5 parts on a day, on this day he may not generate anymore, but on the next day he may generate 5 parts again.
When 4 weeks have expired, then he is not allowed to generate parts anymore permanently.