BO Explorer, as we know by default sorts the data based on values - highest to lowest.  This might be the preferred way in few scenarios, however there might be requirements not to have the data sorted "based on values" by default.  Instead, it should be in alphabetical order (or chronological order in case of DATE related dimensions).

This default sort setting can be changed in the Manage Infospace screen.  Navigate to Objects tab --> Facets.  Each Dimension (or Facet as we call it in BO Explorer) will have a sort option defined with an option to change it.  On clicking the drop-down, there are various sort options displayed (see image below for example).

By default, "Largest to Smallest" option would be selected - meaning the facet would be sorted based on the measure value, largest to smallest.  This can be changed to any other type, based on the requirement.