on an as needed basis：介词短语，固定语法，不需分析。说明书中经常出现的一个短语。不过，这是作定语，应加连字符：on an as-needed basis

意思是：在需要的基础上；根据需要。

They are involved in their child's lives on an as-needed basis and believe rules aren't really necessary because they inhibit growth.
他们以需要的基本水平参与到他们孩子的生活中，认为规则事实上不必要，因为它们抑制生长。
One challenge we face is, how can we capture communication and make the information available to the team on an as-needed basis?
我们面临的一个挑战是，我们如何能够在随需的基础上获得交流并使团队获得信息？
In this way, you don't purchase the software but simply lease it on an as-needed basis.
这样一来，您就不必购买软件，只需随需租用软件。