Abstract: A versioned-data management system is provided with a method for detecting independent changes to a part when an attempt is made to promote a variant of the part. For each variant of a part, there is maintained two identifiers and a flag. The first identifier is the identifier of the last change to that variant. The second identifier is the last-change identifier of the variant which was the source of the drawdown. When the variant is successfully promoted, and there was not previously a variant at the level to which it is promoted, its drawdown-from identifier value is not changed. When the variant is successfully promoted, and there was previously a variant at the level to which it is promoted, the drawdown-from identifier is set to the drawdown-from identifier value of the variant which was previously at the level to which the promote is made.