When you assign the system parameter sys:ApplicationName or sys:MappingName to a Mapping task input in a workflow, the Mapping task input parameter does not read the system parameter values. Instead, the Mapping task input parameter reads the default value of the mapping parameter at run time.

If a workflow contains parallel Mapping tasks and you cancel the workflow while the Mapping tasks are running, any mapping that has yet to start proceeds to run.

The number of mappings that the Mapping tasks specify is greater than the Maximum Worker Threads value on the Data Integration Service.
You cancel the workflow while the mappings that the Maximum Worker Threads value specifies are running and other mappings have yet to start.