tion is made.  After withholding a within-grade increase, the determining official shall determine whether the employee's total performance is at an acceptable level of competence within each 26 weeks following the original due date for the  within-grade increase unless a favorable decision has been made during the interim or action to demote or remove the employee has been taken. If the new determination is favorable to the employee, the effective date of the within-grade increase will be the first day of the first pay period after the acceptable determination has been made. If the new determination is unfavorable, the employee is entitled to a notice of negative determination and notification of the right to reconsideration in accordance with Section 3 of this  article.  The parties agree that any appeal to arbitration which may be filed on the basis of a final decision sustaining a negative determination will be combined with any related grievance which may be concurrently in process.

Section 6--Effective Date/Administrative Error

A within-grade increase shall be effective on the first day of the first pay period following completion of the required waiting period and the employee meets conditions for eligibility.  When, due to administrative error, oversight or delay, a positive determination is made after the waiting period is completed, the effective date of the within-grade increase shall be retroactive to the original due date.  In such cases, interest will be paid in accordance with law and applicable regulations.