Combing Multiple Models

I'm starting to get a feel for Model Builder, but I can't figure this out:

I've got 9 geoprocessing models that are all part of the same essential process. I want to have one model, or script, that will run each one of them consecutively. I tried doing everything in a single model, but I got red exes on some of the tools because I am overwriting some datasets. At the same time, it could be useful to keep each step separated anyway.

So, does anyone know of anyway to automate running 9 models consecutively?

Thanks!