“…Bard and Purnomo [3] formulated and solved the nurse scheduling problem as a multi-objective problem which considered individual nurse's preference. In the past couple of decades, several patient classification systems and acuity systems were developed to aid determination of nursing care, staffing level, and schedule ahead of a shift [7,8,16,23,28,36,50]. It has to be noted that four levels of acuity were considered in this research depending upon the amount of care received by the patients in the north Texas hospital.…”