If the cost center feature is enabled in the Enterprise Installation screen, when purging quantity history Spectrum will remove history only if you have permission to access the job. Spectrum compares the cost center assigned to the job with cost centers in your assigned scheme; if the cost center is not included, then the quantity history will not be purged. In addition, Spectrum compares the cost center assigned to each phase, if applicable, with cost centers in your assigned scheme; if the cost center is not included, then that phase's history is not removed.