JAMM is a tool designed to solve multiple-criteria classification problems. This tool can be used in many different areas e.g. finances, medicine, geology, pharmacology and many others. The methodology that is used within JAMM is called Dominance-based Rough Set Approach (DRSA) to multicriteria classification problems, which concern an assignment of objects (actions) evaluated by a set of criteria to some pre-defined and preference-ordered decision classes DRSA extends the Classical Rough Set Approach (CRSA) proposed by Pawlak [10,11].