Dear Payal,
You could have given a little more information about the nature of your industry, your company's finished product or service, the number of employees etc. Additionally, we also need to know on what attributes the appraisal is conducted. Is it only on the behavioural attributes or functional attributes or both? Anyway, my suggestions are as below:
a) Instead of monthly or yearly, you may conduct the appraisal in October and April of every year.
b) For the employees who join in the months of February to August, their first appraisal will be done in the first week of October.
c) For the employees who join in the months of September to January, their first appraisal will be done in the first week of April.
d) The points mentioned from (a) to (c) above, may not be applicable for the measurement of certain costs and ratios associated with the department(s). The HOD needs at least 8-9 months to bring a change. Therefore, for them, the measurement may be done after a year or even slightly more than a year. For example, if the purchase manager joins in the month of January. Then it will not be possible for him to increase the Inventory Turnover Ratio (ITR) just within three months. Therefore, measurement of ITR may be done in October or even April of the next year.
Thanks,
Dinesh Divekar