All schools have goals to achieve. The appraisal of teachers is only one small part of the larger Performance Management System that can be developed by schools or a system of schools in order to facilitate an effective delivery of their set targets each year, recognize strengths, identify areas that need improvement, and take measures to develop individuals professionally so as to achieve incremental improvement after each cycle of the implementation of the performance management. To be effective, a performance management system requires clear definitions of roles and functions for each level of staff (e.g. teachers, senior teachers, heads of departments, vice-principals, and principals). Well defined roles provide clarity of functions and should at the same time be sufficiently flexible to allow for ad hoc activities and programs that can benefit students and the school, to be implemented without role ambiguities. Another important component of the performance management system would be the collection of statements of competencies needed to fulfill the roles at the level of excellence. Statements of competencies enable each job holder within the school to gauge their relative standing in terms of existing skills and the required skills. The third component in the system is the work reviews that will very often take place twice a year, once in the middle of the year as a mid-term review to determine of work progress, modifications that may be necessary on work targets, and the setting of new targets if required. The fourth and very important component is the professional development of staff through the identification of areas for improvement, and the negotiation between job holder and the reporting officers, as to what kind of professional development program that the job holder may attend when. This paper describes how Singapore schools implement their performance management systems as a developmental tool, where appraisals are not seen only as work evaluations alone, but more as an opportunity for incremental improvement and capacity building of the job holder through proper identification of the required professional development programs, which incrementally works towards school excellence, along with rewards for good performance, with each cycle of the implementation of the performance management system.