What constitutes a good decision table? There are many recommendations provided by well-known experts such as  Prof. Jan Vanthienen.  But it’s always a good idea to see at least one specific example and to analyze its different representations. So, we published a new Challenge January-2016 that specifies a notorious decision model “Calculate Vacation Days”.  We expect that DM vendors and/or consultants will provide their best representations of the proper decision table. Then we will ask Prof. Vanthienen to provide his comparative analysis of different submitted decision tables.