> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spherecast.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Supply chain network overview

> How Spherecast models your real supply chain as a network of nodes and flows it can plan over.

## What this page is for

Spherecast plans your supply the way it actually moves in the real world. To do that, it needs a map of your business: the places you hold and make stock, the partners who supply you, and the channels where demand shows up. You draw that map here, under **Settings → Supply chain network**.

The map is a **network of nodes connected by flows**. A **node** is a place or partner in your supply chain. A **flow** (also called a connection) is a path that stock or demand is allowed to travel along. The planning engine only routes supply where you have drawn a flow — so the completeness of this map directly decides how good your plan is.

## The node types

| Node type             | What it represents                                                                                         |
| --------------------- | ---------------------------------------------------------------------------------------------------------- |
| **Warehouse**         | A location where you store, produce, or fulfill orders. Comes in three types (Central, Satellite, Buffer). |
| **Supplier location** | A supplier's or co-manufacturer's site where they produce or hold your stock.                              |
| **Channel**           | A sales channel — where demand comes from (a marketplace, retailer, B2B account, and so on).               |
| **Region**            | A grouping of warehouses, so you can plan and report by region.                                            |

## The flow (connection) types

| Flow type       | What it does                                                                        |
| --------------- | ----------------------------------------------------------------------------------- |
| **Transfer**    | Stock moves between two warehouses along a valid lane you have opened.              |
| **Aggregation** | One warehouse rolls up into another for planning — the two are planned as one.      |
| **Sales**       | A warehouse fulfills a channel's demand — it ties supply to where orders come from. |

## The five building blocks

Everything on this map is built from five kinds of setup, each with its own detail page:

* [Locations & warehouses](/guide/network/locations-warehouses) — where you store, make, and ship stock.
* [Suppliers & co-manufacturers](/guide/network/suppliers-co-manufacturers) — who supplies or makes your goods.
* [Channels](/guide/network/channels) — where demand comes from.
* [Products, SKUs & BOMs](/guide/network/products-skus-boms) — your catalog and how finished goods are built.
* **Regions** — groupings of warehouses for regional planning.

## How it affects planning

The engine follows your map exactly. Supply flows from a supplier into a warehouse, moves between warehouses along the **transfer** lanes you open, and reaches customers through the **sales** flows that connect warehouses to channels.

That means gaps in the map become gaps in the plan. If a warehouse has the wrong type, a supplier is never connected to the product it makes, or a transfer lane between two warehouses is missing, the engine has no path to move stock there. The demand still exists, but the plan cannot serve it — it shows up as an unservable shortage rather than a recommended order.

## Example

You run a Central warehouse in Ohio that feeds two Satellite warehouses, one in Texas and one in Georgia. A supplier in Mexico produces your finished goods and delivers to Ohio. Each Satellite fulfills its own regional channel.

To plan this, you model: three warehouses (one Central, two Satellite), one supplier location in Mexico, two channels, transfer lanes from Ohio to each Satellite, and sales flows tying each Satellite to its channel. With that map in place, Spherecast can pull stock from the supplier into Ohio, push it out to Texas and Georgia, and cover each channel's forecast.

> **Tip:** Build the map before you chase a planning result. Most "why won't it order?" surprises trace back to a missing warehouse type, an unmapped supplier, or an unopened transfer lane — not to the numbers.