Downtime

The term downtime is used to refer to periods when a system is unavailable. The unavailability is the proportion of a time-span that a system is unavailable or offline. This is usually a result of the system failing to function because of an unplanned event, or because of routine maintenance (a planned event). The term is commonly applied to networks and servers. The common reasons for unplanned outages are system failures (such as a crash) or communications failures (commonly known as network outage). The term is also commonly applied in industrial environments in relation to failures in industrial production equipment. Some facilities measure the downtime incurred during a work shift, or during a 12- or 24-hour period. Another common practice is to identify each downtime event as having an operational, electrical or mechanical origin. The opposite of downtime is uptime. Industry standards for the term "Outage Duration" or "Maintenance Duration" can have different point of initiation and completion thus the following clarification should be used to avoid conflicts in contract execution: "Turnkey" this is the most engrossing of all outage types. Outage or Maintenance starts with operator of the plant or equipment pressing the shutdown or stop button to initiate a halt in operation. Unless otherwise noted, Outage or Maintenance is considered completed when the plant or equipment is back in normal operation ready to begin manufacturing or ready be synchronized with system or grid or ready to perform duties as pump or compressor. "Breaker to Breaker" This Outage or Maintenance starts with operator of the plant or equipment removing the power circuit (Main power breaker at "off" or "disengaged" or "On-Cooldown"), not the control circuit from operation. This still would allow for the equipment to be cooled down or brought to ambient such that outage/maintenance work can be prepared or initiated. Depending on equipment types, "Breaker to Breaker" outage can be advantageous if contracting out controls related maintenance as this type of maintenance work can be performed while main equipment is still on cool-down or on stand-by.