Manufacturer's parts may be replaced with either a compatible alternate part made by the same manufacturer or by an aftermarket part made by a third party manufacturer. Software or print databases that list acceptable alternate parts are available for most industries.
Aftermarket replacement parts are certified by the Certified Automotive Parts Association, which ensures that generic parts are comparably safe and reliable to name brand parts. As of 2015, about 25 percent of aftermarket parts are certified. According to Edmunds, aftermarket parts tend to be cheaper than name brand replacement parts, but their quality varies widely. However, for some older vehicles, aftermarket parts may be the only replacements available.