Maintenance Guidelines

Maintenance is performed at the MACC in order to prevent unexpected outages. Maintenance windows provide predictable schedules for staff and customers. These guidelines are based on MACC Operations and User Committee requirements.

MACC Maintenance windows are scheduled quarterly to accommodate the performance of medium and high risk maintenance work. Low risk work may also be scheduled and performed during the maintenance windows, though it may also be performed outside of maintenance windows. Maintenance will be scheduled during all windows. The list of maintenance to be performed will be published—along with risk estimates—on the MACC web site.
1. Low Risk Work: This is work that while critical can be done with little or no risk to operations. An example is preventative maintenance to one of the CRAC units. We have 3 redundant CRAC units in the room (to give us N+1), so taking any one unit down does not affect overall cooling.
2. Medium Risk Work: This is work that can put the data center itself or some other building occupant at risk. An example of this would be some type of mechanical maintenance to the rooftop dry coolers. Taking down a flywheel unit does not have a direct risk on the data center, but it reduces the redundancy and affects the length of time that the flywheels can support data center operations.
3. High Risk Work: This is work that either can or definitely would affect either the building as a whole, or the data center specifically. Shutting down utility power (DTE), taking more than one generator off-line, or required testing of the generator control system, are examples that would all be considered High Risk.
4. Impact on other building occupants: Low risk maintenance items that are noisy and can negatively impact the other building occupants and must be performed outside of business hours, 7 AM–7 PM weekdays. Medium and high risk maintenance that impacts the building Conference Center will be performed 11 PM–7 AM during the quarterly maintenance windows.

Impact and Risk

Impact on other building occupants?	Low	Medium	High
	Risk Level
No	Perform anytime	Perform during quarterly maintenance window	Perform during quarterly maintenance window
Yes	Perform outside business hours (7 AM–7 PM weekdays)	Perform during quarterly maintenance window	Perform during quarterly maintenance window

MACC maintenance windows are determined as follows:
1. To occur four weekends each year during the months of February, May, August and November
2. Beginning on the third Friday of the month
  1. In the event that this occurs during an ITS Production Freeze, the window will be moved to the second or fourth Friday.
3. Beginning no earlier than Friday at 7 PM
4. High risk work to be performed between 8 PM and 6 AM. Medium risk work may be performed during the entire weekend window.
5. If there is noisy maintenance that is planned for 7 AM–11 PM that could impact the other building occupants and the building Conference Center, their approval is required.