Our main focus of the research was to find out Empirical study on the performance appraisal of KESC employees: A real time case of KESC Pakistan. And identifying the concerns of employees regarding the new Annual Performance Appraisal through qualitative research, their acceptance of Annual Performance Appraisal among employees in different tiers through quantitative research, and examined the perception of KESC employees regarding the organizational justice during performance appraisal on the basis of qualitative research. This research is based on the case study of KESC Change Management, and data is collected from the existing employees of KESC, mainly framed to only those employees available at the survey. The total number of employees of KESC 11,600 out of which 5,700 is Management Staff and 5900 Non management Staff. We have used stratified random sampling technique, and we considered the population consisting of both management and non-management staff we have calculated the sample size of 372 from Macorr sample size calculator. The qualitative analyses also provide an insight about the perception of the employees for the Annual Performance Appraisal.