As the cloud security manager for a financial institution, you are responsible for developing a robust disaster recovery plan for the organization's cloud-hosted applications. One of the critical applications handles real-time financial transactions and is integral to the company's operations. In the event of a disaster, the application's downtime must be minimized to prevent significant financial loss and reputational damage. To ensure business continuity, which metric should you prioritize when establishing the disaster recovery plan for this critical application, and why is this metric particularly important?