Do you agree that the most harder solution in physical security is to intervene to the life, health of the others?

Physical Security is bout protection of assets. T

Assets can have many definations so the physical security implemented is determined on the asset and a thorough vunerability and needs assessment.

There is not a simple yes or no answer to this question. Physical security solutions should be threat and risk based on each individual case. All sites should undergo a threat assessment that should be used during a vulnerability study. Good Operational Requirements agreed between the stakeholders should provide the right solution. Risks should be identified and managed with mitigation methods developed, this may mean that a risk is accepted to ensure staff are not overly inconvenienced by security. However, the best security solutions allow a site to change its security posture as the threat changes i.e. portable controls can be put in place at short notice. These measures should be communicated to staff which encourages their cooperation.   

If you are at a site with a continuous high threat of terrorist attack or a site whose denial would have a critical national impact then it would be proportionate to have strict physical control measures such as vehicle and personnel search points and dual authentication. Whilst these do inconvenience staff , having a good security education program will help.