As a matter of principle it can be stated that long deployment of the same personnel in an organisation is not in its interest, as it proves that the requirement to be perennial and could lead to some claim of permanency. How long it could be is a matter of interpretation in each case, but one year is a safe option and longer the duration the more risky it would become.
I am working in a Travel Company in the Admin Department. My work role is handle the compliance for Security and Facility personnel. Someone ask me this question and advice by legal consultant that Security and Facility Personnel can not do their duties in the same company after an year.
We are working with Security and Facility company from last 4 years. Both services are taking from different Companies.
What is to be watched out is that security personnel should not be allowed to develop any close links with permanent staff and visitors etc.
This will hamper duties.But yearly change is not good and will involve teaching new people about the place and jobs etc.Once in 3 years you can rotate some personnel.
As far facility management people are concerned there is no need to rotate them as they would be familiar with issues, processes and position of all mains, equipment etc.
What is the role of security personnel-routine office security or anything more?
Contractors usually are told to reduce or increase the head counts they accept it but fail to arrange alternatives to replaced /reduced employees which is sad part in contracting agencies.