When we want to describe something that is fulfilling its intended function, we might say it is serving the purpose. However, there are several other ways to express this same idea. We might say that something is accomplishing the task, achieving its objective, or fulfilling its function. Alternatively, it might be meeting its intended use, performing its designated role, or realizing its intended aim. Each of these phrases emphasizes the idea that the item in question is doing what it was meant to do, and can be used to describe everything from a tool to a person's actions.