This figure shows the causes of downtime using a hierarchical stack of seven boxes on three levels. Centered at the top of the figure is a box labelled "System Downtime." This box is connected to two more boxes on the second (lower) level labelled "Unplanned Downtime" to the left, and "Planned Downtime" to the right.
The "Unplanned Downtime" box is connected to two more boxes on the third level, labelled "Computer Failures" and "Data Failures."
The "Planned Downtime" box is also connected to two boxes on the third level labelled "Data Changes" and "System Changes."