Generic and specific resources
If you do not know the name of the person you will get in your project team yet, you can add a resource to the resource sheet with a generic title.
For instance, if you put out a vacancy for a test consultant, you create a resource called ‘Test consultant’. If you have vacancies for three test consultants, you could create three generic resources each for 100% availability or just create one generic resource with 300% availability.
Generic resources should have the field generic set to ‘Yes’ and can be recognized by the ‘two-little-heads’ symbol in the indicator column (only available in the 'professional' version of MS Project).
Generic resources are assigned to tasks exactly the same as specific resources are assigned to tasks.
When you use a resource, the respective tasks will calculate correctly and the moment you know who is going to perform the task (specific resource) you can replace the generic resource by the specific resource easily.
When you use a generic resource for tasks later in the schedule, create a ‘dummy’ resource calendar as well, so you take an average into account for holidays and other forms of non-availability.