A departmental security plan is a document that departments and organizations prepare that gives an overview of their security situation. It looks at the types of security risks that an organization may face. It would also look at, perhaps, some of the mitigating circumstances, mitigating controls, that might be in place, and also at what types of activities or actions that organization might need to do to deal with those security risks. It gives the organization that overall view of the types of security risks that they face.