Hi!
I am a Director of Supply Chain Consulting, and I think I have some information that can help you. I actually have a Supply Chain transformation roadmap that I implemented in my previous company. It worked well. In my time there, we also transitioned from decentralized to centralized purchasing. Not a fun task as all!
I'd love to talk to you more about my experiences. My contact email is:
lejeunem@sms-inc.net