阿山 15 年来一直是 FixMyCar.com 的营销者和网站管理员。为了让用户对网站更加满意，他和开发者团队花费了很多心力。然而，最近的性能指标显示，该网站的速度随着时间推移显著下降。 哪个长期维护计划可以通过限制某些影响性能的指标来帮助解决这个问题？

A performance budget is a long-term maintenance plan that sets limits on various performance metrics (e.g., page load time, image size, JavaScript bundle size) for a website. By establishing these predefined thresholds, it ensures that new features or content additions do not degrade overall site performance over time. This proactive approach helps prevent the gradual slowdown experienced by FixMyCar.com. A performance maintenance team is a group of people, not a plan. A long-term performance audit is a one-time or periodic review, not an ongoing preventative measure. A separate testing plan outlines how testing will be conducted but doesn't inherently set performance limits.