There is no standard formula for determining a data center's physical security budget allocation. Anticipated growth of your data center's physical security system during the time frame of your budget is a major determining factor. Additionally, strategies vary depending on whether you're budgeting for an existing data center's physical security or if it will be for a future project.
If you are attempting to estimate what you will require for a budget to maintain the installed components and systems in a data center where physical security has been installed, the integrator who is contracted to provide you with the service should be able to provide you with an exact service and maintenance number. However, I would recommend adding 20% to that number for any unforeseen, outside of contract maintenance costs.
For future project budgeting, you should be able to get a hold of what your facilities department has planned for projects that require physical security and estimate what the security costs related to those projects will represent. You will need to determine what the unique physical security requirements are for each project. Using 1% to 1.5% of a total project's construction costs should suffice.
The cost you incur as opposed to what is charged back to projects and other departments will generally fall into one of the four categories below:
ABOUT THE AUTHOR: Thor A. Mollung, CHSII, Managing Director, Security Consultant, has over 20 years of experience in the industrial security industry with companies such as Fidelity Investments, Mellon Bank and State Street Corporation. Mollung is a member in good standing of the American Society for Industrial Security (ASIS-International), the National Fire Protection Association International (NFPAI), and the American College of Forensic Examiners Institute.