Dear Ayisha,
What is your product or service? What type of sales do the salespersons do? You cannot have performance appraisals for salespersons in isolation.
It appears that you do not have a proper Policy on Performance Appraisal (PA) well in place. When employees join the company, during induction itself they should be told when their appraisal will take place. The salient features of policy could be as below:
a) Appraisal may be done quarterly. The appraisal cycle of one year is too long. Nevertheless, a salary hike may be done a son 1st April or 1st Oct.
b) Employees who join in between, when their first PA will take that can be decided in the policy.
c) % of salary hike should be linked to the score of PA.
The important point is PA concentrates only on individual performance. We need to go beyond and measure the business performance. For this, you need to have a well-designed policy on Performance Management Systems (PMS). There was a query in this forum on PMS. I have given a reply to this post. Click the following link to refer to the reply:
https://www.citehr.com/511936-pms-company.html
Though the heading of the heading is for IT companies, the reply is applicable to all types of industries. In the above link, you will find several other links. Go through all the links patiently. It will improve your awareness of the subject.
For further doubts, you may call me on my mobile number.
Thanks,
Dinesh Divekar
+91-9900155394