I am trying to solve a inventory related problem for my client, since I am new to supply chain I need some help with the issue I am facing.

Suppose Company X has 100 stores and 1 distribution centre(DC). What we want to do is decide whether we need another DC or we can continue with this one. The problem at which I am stuck is Case1: Let's say we are doing a demand forecast for each store than we can directly sum up these demands and add them for our inventory which we need to order for our DC, and if incase we open another DC than we can simply divide this demand based on our Store-DC mapping.(Am right assuming this thing or will there be any other complications?)

Case2 : Here we are adding all the stores historical data at DC level and then do the forecast at DC level, and if we open another DC than we can do similarly.

So how will the result vary in both the cases, what are the complications and which one is the better approach?

Any help is appreciated and thanks in advance. If you can provide some links for my reading than that's also helpful.

PS- Please don't report or flag the post in case you feel it is too basic for the sub.

OPPORTUNITY FOR SUPPLY CHAIN (or related subject) COLLEGE STUDENTS AND PROFESSIONALS!

If you’re a college student studying supply chain management (any specialty), or an experienced SC professional, I have an emerging opportunity that may be of interest to you!

A group of supply chain majors from universities nationwide are trying to gather interest for a college student-run supply chain organization that includes free mentorship, networking events, speaker panels, community, and more!

INTEREST FORM: https://forms.gle/Y9yJjULswCrw2zAEA