Avoiding Using Negative Driver Data Values
Driver data with negative values can create challenges for the allocation engine that can result in unexpected and unusable results. The allocation engine uses the driver values found at each destination location as a numerator in the ratio Driver Value / Sum of All Driver Values. This allocation ratio is multiplied by the source value to determine the AllocationIn amount to apply to the destination. Using a mix of positive and negative driver values creates cases where the denominator is no longer accurate and can cause inflation and deflation of AllocationIn amounts in the rule results. These results are very difficult to explain and justify, so it is best practice to avoid this situation entirely.