"Performance Improvement Plan". The "PIP culture" mentioned is a culture where there is an (perhaps unspoken) quota of people that need to be put on PIPs, so they are quick to pull the trigger. Very uncomfortable as it keeps people on edge.
Personal Improvement Plan. Usually used as either a blunt instrument to goad people into working harder or a sneaky way to fire people. Topped with a sauce of double-speak of course.
