If we were to follow by the books - PIP means you did not perform up to company's standards, hence being placed in a performance improvement plan.

However, knowing how Malaysian companies are like, PIP is one of the most overused and unaligned / out of touched thing to use on the employee even though we know it's very unfair towards the affected employee. General consensus and overall comments on here reflects as such and I think you can get an idea what's going on as well.