The effective value is the maximum of the linked values
Documentation
Definition
If an object is linked to other objects then implicit classifications my exist. Since single-valued characteristics allow only one value, multiple implicit classifications from other objects together with a potentially existing explicit classification of the object itself create a conflict. This conflict is resolved by declaring the maximum or the minimum of the values as the effective one.
Use
If the checkbox is selected, than the maximum of two values is effective. In order to compute a maximum, an order of the values is needed. In case of characteristics with explicit values, the order is just the order in which the values are entered. In other cases, the default is the lexicographic order. You can define your own order by implementing the BAdI CLS_CHARACTERIZATION, method GET_EFFECTIVE_VALUE..