= The best approach for developing a physical access control policy for the organization is to conduct a risk assessment to determine the security risks and mitigating controls that are relevant and appropriate for the organization's data center. A risk assessment is a process of identifying, analyzing, and evaluating the information security risks that could affect the availability, integrity, or confidentiality of the servers, applications, and data that are hosted in the data center. A risk assessment can help to determine the likelihood and impact of the unauthorized or inappropriate physical access to the data center, such as theft, damage, sabotage, or espionage, and the potential consequences for the organization and its customers, such as service disruption, data loss, data breach, or legal liability. A risk assessment can also help to identify and prioritize the appropriate risk treatment options, such as implementing technical, administrative, or physical controls to prevent, detect, or respond to the physical access incidents, such as locks, alarms, cameras, guards, badges, or logs. A risk assessment can also help to communicate and report the risk level and status to the senior management and the relevant stakeholders, and to provide feedback and recommendations for improvement and optimization of the physical access control policy and the risk management process.
Reviewing customers' security policies, developing access control requirements for each system and application, and designing single sign-on (SSO) or federated access are all possible steps that the organization can take after conducting the risk assessment, but they are not the best ones. Reviewing customers' security policies is a process of understanding and complying with the customers' expectations and requirements for the security of their servers, applications, and data that are hosted in the data center, and ensuring that the organization's physical access control policy is consistent and compatible with them. Developing access control requirements for each system and application is a process of defining and implementing the specific rules and criteria for granting or denying the physical access to the servers and applications that are hosted in the data center, based on the roles, responsibilities, and privileges of the users, and the sensitivity and criticality of the systems and applications. Designing single sign-on (SSO) or federated access is a process of enabling and facilitating the authentication and authorization of the users who need to access the servers and applications that are hosted in the data center, by using a single or shared identity and credential across multiple systems and domains. References = CISM Review Manual 15th Edition, pages 51-531; CISM Practice Quiz, question 1542