Order of retention.

When determining the order of retention in a reduction in force under this part, an agency must classify competing employees on the appropriate retention register on the basis of four factors (tenure of employment, performance, veterans' preference, and length of service) as follows: (a) By tenure group, with the competitive service tenure group and the excepted service tenure group listed on separate retention registers; (b) Within each tenure group, by performance credit in descending order as determined in § 351.503, as augmented by veterans' preference as described in § 351.504; (c) When two or more competing employees have the same performance credit, as augmented by veterans' preference as described in § 351.504, the competing employees are further ranked in descending order by tenure subgroups (as described in § 351.502), with tenure subgroup I listed ahead of tenure subgroup II, and then by years of service beginning with the earliest service computation date, as computed under § 351.505.