How does MS Project share the same resources (people) among separate projects?

Christian,

You need to create a "Resource Pool".

A resource pool is a Microsoft Project file that should contain only Resource Information - ideally it is a record of all the resources you are likely to assign to tasks undertaken by your organisation.

Once you have created and saved the Resource Pool open a project which you wish to have "Share" the resources from the Resource Pool. From the Tools menu select either "Share Resources" or "Resource Sharing" depending on your version of MS Project - in the "Sahre Resources" dialogue box select the share resources from option and select the "Resource Pool" file from the drop down list. By default the "Pool Takes Precedence" option is selected, this implies that in cases where information about resources in a project and the resource pool "conflict" that the information in the resource pool is deemed to be correct. This can occur in situations where a project already has a resource called Jim Dale and he also exists in the Resource Pool the project is looking to share resources from, if the cost rate or working time for Jim Dale differs between the 2 records then the "Pool Takes Precedence" option applies.

NOTE: If your users have a habit of naming people in their own way or are bad at spelling you may have duplicate resources arising from this process - for example in the pool there may be a resource called Jackie Smith and in the sharer file there may already be a resource called Jacky Smith - if the project is set to share resources from the pool a new resource called Jacky Smith will be added to the pool as she exists in the sharer project.

There is a lot more to shared resources and the Resource Pool but this should get you started.

Happy planning

Dominic