A security mix is a combination of security measures that, when properly deployed, can effectively protect assets. A good security mix incorporates multiple types of security measures at sufficient levels to provide adequate security. Note the key phrase in the last sentence…at sufficient levels.
In a chapter I recently wrote for a Retail Security textbook, I discussed the concept of security overkill. Security overkill occurs when security measures are over-deployed given the level of risk to assets. However, security overkill is better than engaging in the concept of security otherkill – where security resources are directed at a non-existent problem.