Industrial electronic repair services repair, overhaul, refurbish, and warranty industrial electronic equipment. They vary widely in terms of services offered. Some companies perform on-site or field repairs in order to minimize customer down-time. Others perform bench repairs, working at their own facilities. Calibration services compare instrument and equipment outputs to established standards. Remanufacturing services overhaul or rebuild industrial electronic devices. Companies that offer installation and start-up services perform training and test equipment according to customer specifications. Original equipment manufacturers (OEMs) and warranty-authorized shops perform repairs according to the terms of customer warranties. Preventive maintenance and service contracts are proactive programs for performing maintenance in order to prevent problems. Replacement and exchange programs provide customers with new or used units while damaged instruments or equipment are repaired. Some industrial electronic repair services rent or lease equipment. Others sell new, used, or refurbished products. Companies that specialize in upgrading existing product lines can add completely new components, or replace existing components with improved or updated units.