Duplicates are identical applications across different products for the same part type. For your customers, it looks like you are selling identical parts with two different part numbers. Note: This validation does not look at any attributes or descriptions but only the application data. To fix a duplicate you typically need to specify additional information such as engine details, transmission, qualifiers etc.
These are flaws in logic within one product. The rule of ACES is: “less is more”. In ACES you only make a selection for a subconfiguration if you want to exclude the values that you are not selecting. Example: By selecting one submodel you are communicating to your customers that your product does not fit any other submodel but the one selected. The PDM overlap validation shows you two or more application records within one product that have flaws in logic by one application having a selected value for a specific subconfiguration and another application not having a similar selection, which means that all values of that subconfiguration are valid. You are therefore making opposing statements: “This product fits every value of this subconfiguration” and on the other side: “This product only fits on this subconfiguration”