Supply Chain Management is a very very broad area, so there are so many different roles within SCM. There are so many different functions that happen within SCM, listed below are a few
1 - Warehousing
2 - Transportation
3 - Demand Planning
4 - Supply Planning
5 - Manufacturing
6 - Procurement
7 - Inventory Management
8 - Order Management
9 - Vendor Management
10 - EDI
Again within all these areas, there are sub areas, for example under Warehousing there is Order Fulfillment, Inventory Management, Physical Inventory, Cycle Count, Receiving, Putaway, Labor Management, Slotting, Value Added Services etc.
Also there are two major aspects to every single area, there is a Business aspect, which will be managed by a business user, this role will define processes, the different steps that need to be executed to complete a function. Then there is the IT aspect, these are the Systems that support these functions, which will be still run by the business user, but supported by the IT user.
So it is very broad area with a lot of moving parts to it. The bigger the organization the more complex it gets because every player in the Supply Chain is trying to get whatever cost savings they can get, if the Supply Chain is let us say $100B, then wherever you can save a few millions will be a win, that is when it gets complex. Also there is something called Finance Supply Chain, how the funds move through the whole cycle, which is yet another thing.
Also check out my book Puga Sankara's Supply Chain Blog - that is a must read before spending Hundreds & Thousands of $$$ on your MBA or Masters Degree to get the best ROI or before starting your Entrepreneurial journey.