Objective setting for KRA &KPI

Dear Experts,

am very fresher to appraisal module, needs to customize for appraisal,objective settings, KRA & KPI where it requres multiple columns for KRA ,against that KPI

Pesently it is processed manualy ie., in the hard copy employee fill up the KPI against KRA with % of weightage,self rating and KRA is given be the HOD with % of weightage

After employee rating HOD will award the rating

Please guide me how can i incorporate the above

Kindlly provide any step by step doc. if available, points will be awarded

Thanks in Advance

San