Following the subschema generation principle ("all valid instances of the subschem must be valid instances of the full schema") it should be poosible to restrict the multiplicty range of associations and attributes in the process of creating a subschema. Users would thus be able to make attributes or components mandatory in their use case, e.g. by restricting 0..1 to 1..1. This would significantly increase the expressiveness of subschemas for particular services.
Proposal: the tool should allow to narrow down the multiplicity range by allowing to edit the min/max definitions of the range in the described way, i.e. min may be increased up to max, max may be decreased down to min.
Fixed in 2.1