Microsoft Project

Hi Neil

Thank you for your question.
You can incorporate resource non-availability caused by things like holidays and other commitments by adjusting the working time calendars for the resources in question.

To do this switch to Resource sheet view then double click on the name of the resource in question.
From the dialogue box that opens click on the Change Working time button (it's on the general tab). From here you can create exceptions as needed to the resource's calendar. You can also adjust the underlying default work week pattern in the Work weeks tab.

I hope this helps - do let me know if you have any further questions.

Kind regards,
Andrew