PIP stands for Performance Improvement Plan. It is a part of the Policy on Performance Management System or Policy on Performance Appraisal. You cannot have separate policy only for PIP.
In the either of policies mentioned above, you may add an Appendix on PIP. It may specify who will be placed under PIP, why they will be placed, how long they will be placed, what Manager of a person who is placed under PIP will have to do, and what will happen if the performance does not improve on completion of PIP. You also need to include clause on process on separation for failure to improve the performance.
29th June 2017 From India, Bangalore