This is a popular term used to describe the essential services required for day-to-day operations. If a business operation cannot be interrupted under any circumstance without hurting production, then this operation is considered the business’ mission critical because it is indispensable. Databases and process control software are considered mission critical to a company that runs on mainframes or workstations. Emergency call centers, computerized hospital patient records, data storage centers, stock exchanges and any other operations dependent on a computer and communication systems have to be protected against downtime or shutdowns due to the system's mission-critical functions.
Investment dictionary. Academic. 2012.