Detection of independent changes via change identifiers in a versioned database management system

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. When the promote of a variant fails, the drawdown-from identifier is set to the last-change identifier value of the variant which is first in the search path beginning at the level to which the promote is being made. The flag indicates whether the variant can be promoted by normal means, or must be promoted using promote-force. The identifiers and flag are used to identify independent changes and control data integrity in the VDMS at promotion time.