For most things you should be able to update automatically. There are some
functions that won't work on a closed workbook - such as a VLOOKUP() that
needs to look something up in the closed book.
In Tools | Options, on the [Calculate] sheet, make sure that Update Remote
References is checked, and you may want to go to the
Tools | Options and on the [Edit] tab, clear the Ask to Update Automatic
Links checkbox to get rid of the nag.

Now obviously the closed workbooks are not going to get the changes made in
the open, Summary, workbook - do the same setup in them and at least they'll
update when opened. Now, if you set up these inter-workbook links in a way
that they become a circular reference kind of loop, all bets are off.

"Fred Ernst" wrote:

Is there anyway to have destination cells update in an open workbook from
source cells in closed workbooks?

I have a Summary workbook that contains links to many closed workbooks in
the same directory.

The closed workbooks also have some links to the open Summary workbook, so
that when I make a change to a source cell in the Summary workbook a
calculation would be done in the destination cell of the closed workbook and
another destination cell in the Summary workbook that contains a link to the
calculation result in the closed workbook will update.

Thanks,
Fred