You can save time by appropriately suspending objects such as the Topology Set and 3D Mesh objects. The Suspend Object Updates command toggles the state of suspension of an
                object. By suspending an object, you prevent it (and objects that depend on it) from being updated in response to
                changes to other objects.
For example, the Topology Set object depends on the
                    Geometry object, and, when not suspended, will be
                reprocessed each time the geometry is changed. If you want to make several changes
                to the geometry, you can skip the intermediate processing of the topology by
                suspending the Topology Set object. Note that the
                    Topology Set object is initially suspended when you start a
                new case.
To process a suspended object, unsuspend it.
An icon overlay indicates whether or not an object is suspended. Icon overlays are illustrated in Table 1.1: Icon Overlays and Text Styles.
Note:  The Undo command cannot properly undo a suspension change (for example, to the Topology Set object); attempting to undo a suspension change can lead to an inconsistent state.