When building manufacturing routes you can make them really specific to resources. This is fine if you have that need but if resources change and there are large pools of resources that could do a job then you might want the scheduling engine find a resource based on a rule you provide. For example if you want to find a resource based on a capabilities you can tag these against the resource. Then when setting up the route don’t assign a resource specify the capability that you need to complete that operation.
This can be used for example if you have production presses that are rated for a specific tonnage or through put. If you need a specific rating to be able to do an operation you could add capabilities to the resource and the route to find a resource.
This is a quick walk through of the concept in AX.