Changes to SWWL Schedule. Sign-up SWWL may be cancelled, due to operational reasons, by mutual agreement between the employee and his supervisor. Such cancelled leave will be rescheduled by March 31. It must be understood that this Agreement in no way affects the Company’s right to determine the time to be scheduled on the sign-ups nor the scheduling of single days off. Both of these are subject to staffing and productivity requirements and approval of the Company.