A Practical Guide to One of the Most important Decisions in Dynamics 365 Supply Chain
“Should this be a new site, or just another warehouse?”
It sounds simple.
It is not.
This decision quietly influences planning, costing, financial reporting, transfers, and future scalability. Get it right, and the system feels intuitive. Get it wrong, and you’ll be explaining workarounds to Finance for years.
So let’s break it down – without jargon, and with real-world perspective.
Sites vs. Warehouses: The Short Version
- Sites define operational and financial independence
- Warehouses define physical storage and execution
If you remember nothing else from this article, remember that.
What a Site Really Means in D365
A Site in Dynamics 365 is not just a location – It’s a planning and accounting boundary.
A site affects:
- Master planning (MRP/Planning optimization)
- Inventory ownership and valuation
- BOMs and routes
- Production costing and WIP
- Transfer Accounting
- Financial reporting and dimensions
When you create a site, you are telling they system:
“This location plans, sources, produces and accounts for inventory independently”
This can be very powerful.
What a Warehouse Really Means
A Warehouse, on the other hand, is about where inventory physically sits.
Warehouses:
- Live under a site
- Share planning and costing logic
- Can be physical or logical
- Support Advanced WMS independently
Creating a warehouse says:
“This is another place to store or process inventory – but it belongs to the same operation”
The Question You Should Always Ask First
Before you look at org charts or facility maps, ask this:
“Should this location generate its own planned orders when I run MRP?”
- Yes → You’re talking about a Site.
- No → You’re talking about a Warehouse.
The Financial Impact (Where Decisions Get Serious)
This is where “To site or not to site” stops being theoretical.
Sites Affect the General Ledger
In most implementations, Sites drive financial dimensions such as:
- Cost center
- Business Unit
- Region
- Profit Center
That means:
- Inventory value is tracked by site
- COGS is posted by site
- Variances roll up by site
- Margin analysis becomes straightforward
If Finance wants to see it on the P&L or balance sheet, it usually needs to be a Site.
Inventory Ownership Lives at the Site Level
Inventory is financially owned by:
Legal entity + Item + Site
Warehouses under the same site:
- Share inventory value
- Do not create separate balance-sheet assets
- Are operational, not financial, boundaries
If two locations should not share inventory value, they should not share a site.
Manufacturing Makes the Decision Even Bigger
For manufacturing companies, sites control:
- Standard cost versions
- Labor and overhead absorption
- WIP accounting
- Production Variances
Two plants make the same item often:
- Have different labor rates
- Have different overhead models
- Result in different costs
That requires separate sites. Warehouses cannot do this cleanly.
Transfers: Physical vs. Financial Reality
Another litmus test:
Warehouse-to-Warehouse (Same Site)
- Physical movement
- No Financial posting
- No Ownership Change
Site-to-Site
- Inventory issue and receipt
- Financial posting
- Optional markup and freight capitalization
- Possible intercompany accounting
If Finance expects a transaction, you probably need a site.
A Common Mistake (And Why It Happens)
Many teams default to warehouses because:
- They feel safer
- They’re easier to add
- They don’t immediately impact finance
But later, the business asks for:
- Inventory value by location
- Margin by plant
- Separate cost structures
- Cleaner financial close.
At that point, converting warehouses into sites is painful, disruptive, and expensive.
The Conservative Best Practice
Start with fewer sites and more warehouses – unless independence is clearly required. But don’t confuse conservative with short-sighted. If the business:
- Plans independently
- Costs independently
- Reports independently
Then it is independent, whether it wants to be or not.
A Simple Decision Matrix
| Requirement | Site | Warehouse |
|---|---|---|
| Independent MRP Planning | ✓ | ✕ |
| Separate inventory ownership | ✓ | ✕ |
| Different production costs | ✓ | ✕ |
| Shared sourcing and planning | ✕ | ✓ |
| Physical storage variation | ✕ | ✓ |
| Financial reporting by location | ✓ | ✕ |
Final Thought: This is not Just a Supply Chain Decision
“To site or not to site” is:
- A supply chain decision
- A finance decision
- A future scalability decision
The best implementations align Operations, Finance, and Architecture early – before the first site is ever created.
Because in Dynamics 365, structure is destiny