Project portfolio management

I am at the final stage of my Masters
(Project Management). The last hurdle is a dissertation to be issued June 2nd. My dissertation is titled ‘The added value of project portfolio management’. I value your opinion regarding this subject. Is project portfolio management conducted at all? Where? Does it relate to clarity of strategy, alignment, fact based management, adoption of the plan-do-check-act cycle, and pro-activeness? Is there any added value? For more information see http://home.planet.nl/~avtnl.

Kind regards,
Anthony van Tilburg
The Netherlands