6th International Conference on Environmental Issues and Management of Waste in Energy and Mineral Production (SWEMP 2000), Calgary, Kanada, 30 Mayıs - 02 Haziran 2000, ss.669-672
The jump in levels presented in the control charts occurred due to the annual preventive maintenance schedules. However, after four months the plant went back to its level prior to preventive maintenance. This suggests that the use of preventive maintenance in four months period is appropriate. This was also supported by the stratification at the end of the first four months period. One week of four preventive maintenance periods per year can be better than Four weeks of one preventive maintenance period.