Dear Madhavan,
It appears that you do not have a proper policy on Employee Performance Appraisal. How do you measure the performance? Do you have well defined KPIs and KRAs? What is your performance cycle? Is it quarterly or half-yearly?
Whatever the designation of the employee may be, whether he/she is placed on probation or not, their performance measurement starts right from the first day onwards. Initially give the lesser targets. As the employee settles, you may increase the target gradually. For additional information, you may refer to the following link. It is my reply to the last query on performance appraisal:
https://www.citehr.com/521259-perfor...ny-method.html
Thanks,
Dinesh Divekar
+91-9900155394