What is PPM in maintenance field?

Planned preventive maintenance (PPM), more commonly referred to as simply planned maintenance (PM) or scheduled maintenance, is any variety of scheduled maintenance to an object or item of equipment.

PPM is Planned Preventive Maintenance. It is done periodically. It can be daily, weekly, monthly, quarterly, semi annually or Annually. Every type of PPM has a slightly different checklist, the longer the period of duration, the longer is the checklist. PPM Master plan is prepared for each and every equipment of the plant and it is approved by the assigned authority. PPM is very necessary to maintain the equipment in goo working condition. PPM also helps to minimize the Corrective Maintenance of the equipment.

Planned Preventative Maintenance or Periodic Preventative Maintenance. They both serve the same purpose. Basically, it is to eliminate machines sudden break down and make sure that the equipment performance is efficient.   

Project Portfolio Management (PPM) is the centralized management of the processes, methods, and technologies used by project managers and project management offices (PMOs) to analyze and collectively manage current or proposed projects based on numerous key characteristics.

PPM is repair that time due to production so its repair temporary

Planned preventive maintenance

PPM is periodic preventive maintenance 

Planned preventive maintenance (PPM) .example a rotating machine having a problem  but can not be repair that time due to production so its repair temporary and planned for maintenance at shut down time

PPM means Planned Preventive Maintenance. The schedule already planned by Maintenance Planner section or Section Head for any maintenance or outage job. Everything related to appropriate maintenance or outage already discuss earlier before time is coming.