Difference Between DFSS and DMADV

DFSS and DMADV are NOT the same thing.  At my company, DMADV is used to assist in developing new processes (and is light on statistics) whereas DFSS is used to optimize product designs before launch (and is heavy on statistics).  All DMADV can be construed as DFSS, but not all DFSS is DMADV. 

I draw the line between them based upon DMADV being mostly good project management with a focus on new processes, and DFSS being the set of  modeling and analysis tools/methodolgy used to predict the probability of a failure, and then to optimize the design to minimize the probability while maintaining all requisite process capabilities/customer expectations.