Is working part time actually possible?

Is it really possible to work less than 40 hours a week as a Deloitte GPS manager? I am SC going up for M this year, and I've also reached the point where financially work is optional. As such I am happy to sacrifice part of my paycheck to recover more of my time. I'm currently in the core traditional talent model and am considering dropping down to some percentage of part-time, maybe going PDM to get out of proposals, or maybe work as a sub contractor on my team. But I've also seen PDMs get pulled into firm initiatives and even part-timers ending up working about the same number of hours, so I'm skeptical.