For common events, The following is the mapping methodology

a) Any event which can be common must be drawn as a common event. (A normal
event cannot be
later instatiated to be common. so it must be drawa as a common event at the
first instance itself)
b) The mapping for the first instance is done like any other event.
c) For instatiating other common events to be common to this instance,
choose
the common events first instance
in the MAP window, press associate and when the window moves out of view,
click
on the common event that is
to be mapped. The mapping for this set from now on will appear in the MISC
window.
d) The same procedure is applied for mapping other common events to the
first
instance.
e) There can also be many such sets of common events. In each case the first
instance should be
mapped as in step a) and the remaining steps as described earlier.