Katie is available to relieve your engineering and management staff, which is a much overlooked necessity in todays construction industry.  It is sometimes better to outsource relief as team members can be reluctant to take leave as they do not want to be "superseded" by a zealous or ambitious colleague.   It also just might be the case that you do not have the resources to allow leave when it is asked for.    Katie quickly adapts to new environments and is an affable team player who can easily integrate into your project team and just get the job done, giving your team  member peace of mind that the project will not fall to pieces while they take a short break.