I have some use cases in mind, where the service level objectives are not arbitrarily defined by the initiator, but 
rather defined by the agreement factory. Take the example of a data transfer service, which guarantees the upper bound 
of the time needed to transfer one file from a given source to a given destination. In this scenario it would be 
desireble to have this service level objective defined in the template through the creation contraints (where the file 
transfer time upper bound is a parameter to be filled in by the initiator).

So, the question is: can the creation contraints be used to define  the service level objectives in a parametric way, so
 that the initiator only needs to provide values to the parameters included in the expression?