Currently I have 3 projects I'm managing. One is the in initiation stage. One in controlling. And one in the closing.
For each of these projects I have different concerns with my resources.
For the project that I'm initiating I'm working with the resource managers to make sure I'm on their plan to have the resources I need based on my project requirements. I keep them in the loop if things slip a little or if it looks like we may be adding scope.
For my project that is in the the controlling phase I have to box out my resources as others try to "get a little of their time". There is a fine line with this, because many times you need to trust your resources to manage their own time so they can help out on other projects too.
In my project that I'm closing out I've kept the resource manages in the loop as to when I was going to release the resources so they could be assigned elsewhere.
This is a delicate yet complicated dance that we do as Project managers. The key to this is communication with the project team and the resource managers.
Look ahead for your needs or you will be behind before you know it ....