I am having the same requirement, please let me know the solution, how to tackle this problem.
first of all, capacity of the workcenter is not getting blocked even after I have created maintenance order for the Equipement ( at which workcenter is assigned). Please let me if I am missing any integration data.
In Equipement , at Location tab we have mentioned the workcenter. (production). Then I created the maitenance plan ( say 16/11/2007-19/11/2007) and released the same. Now When I entered at CM27 system is still showing the available capacity on the above mentioned days.