Dear Sangitha,

If u r conducting the performance appraisal first time, conduct an awareness or orientation to the employees about the appraisal. So that they can understand better about the system .

After developed the objectives of the performance Appraisal system, devide the total PA system into few major area like
1.job responsibilities i.e Tasks vs achievements
2.competencies/ behavoiur skills.

Aslo provide the guidelines for the apparisar in the system itself.
The Appraisal system generally depends on few indicators like Participation (It generally depends on the Job desription of the employee), Coordination , Implementation of Planning, meeting the deadlines,recurring tasks etc. U can aslo put the indicator like accountable for not doing.

The indicators varies from company to company.

All The best

Regards
Hasini