Improving engine reliability and ease of maintenance is a major objective for the F135. The engine has fewer parts than similar engines, which improves reliability. All line-replaceable components (LRCs) can be removed and replaced with a set of six common hand tools. The F135's health management system is designed to provide real time data to maintainers on the ground. This allows them to troubleshoot problems and prepare replacement parts before the aircraft returns to base. According to Pratt & Whitney, this data may help drastically reduce troubleshooting and replacement time, as much as 94% over legacy engines.