Deletion of work center category

We have a req to delete the capacity category for a work center . We have two existing categories 001- machine , 002 - person. And now we need to delete 002 , but as we are trying to delete, system shows an error that capacity still being used . So on checking in the where used list of work center in cr40 , i can see that the work center is being used in numerous production orders as well as maintenance orders . So is this the reason , system is not allowing to delete ? Is there any alternative way of deleting category?

And moreover how can we best understand table KDEB ?

Pl suggest