You can specify which data types are allowed as input or output in you DMN decision table diagram.
Procedure
Open a DMN decision table.
Click an Input or an Output column header.
Click Configure column. The dialog opens.
Enter a name.
Specify a data type. You can create a new object of type Item definition or use an already existing.
Click OK.
You have specified an Input or an Output column.
Tip
Click F2 to open the dialog. Use the Tab key and the arrow keys to specify a data type. Make your entries and press Enter.