What are key elements of organizational design for a newly formed Supply Chain Strategy and Excellence group? The remit of this group is on process governance and overall solutions for issues and process related challenges in the global supply chain. What levels of authority (grade/position level) is needed to be effective? What are the key capabilities such an organization must possess?

When it comes to Supply Chain Excellence (and process governance) I see it more as what we call a Center of Excellence. If this is the case then I would suggest that my college Anna can elaborate on that. 

But if it comes to more Strategic and long-term processes and connecting those with outside in perspective, then I can share some more from our side.

In my experience, the org design for a supply chain strategy & excellence group should mirror that of the broader organization.

How is the broader business organized:  1)  strong central/global structure with no/limited decision making in region/market, or 2) regional structure wherein each region has the necessary functions to operate independently from others, with minimal guidance on must-do's from the central global leadership, or 3) fully local authority, each region/market operating independently?

Answering the above question should guide how you design your supply chain strategy & excellence group.  For example, it doesn't make a lot of sense to design your SC strategy/excellence group to have strong global/central authority if the business is set up to operate using model 3 above.  Your global team will likely be seen as an impediment to progress.  So, design with that in mind and grant decision making accountability in line with this as well.