Modeling concepts

Before you start your journey to load your data in frePPLe, we need to explain you a few modeling basics.

Concepts as items, locations, customers, demands… don’t need a much of an introduction. But, some other concepts need some introduction before you get your hands dirty.


A buffer is a item+location combination. It is a inventory point for an item at a specific location.

There are three different ways to replenishing a buffer:

  1. The item can be purchased from a supplier

  2. The item can be transferred from another location

  3. The item can be manufactured

It is possible to define multiple replenishment methods for a buffer: for instance “buy from supplier X or supplier Y”, “make the item or buy the item”. In such a case the planning algorithm will automatically choose the appropriate method.

Buy: Replenishing with a purchase order

The Purchasing section of this wizard will guide you through this.

By populating the supplier and itemsupplier tables we define that a buffer can be replenished with a purchase order to a specific vendor.

Modeling - Purchase operation

Transfer: Replenishing with a distribution order

The Distribution section of this wizard will guide you through this.

By populating the itemdistribution table we define that a buffer can be replenished with a distribution order (aka transfer order or stock transfer order) from another location.

Modeling - Distribution operation

Make: Replenishing with a manufacturing order

The Manufacturing BOM and Manufacturing Capacity sections of this wizard will guide through this.

A number of tables are required to define the operation, its produced materials, its consumed materials and its capacity usage. The diagram below shows the buffers as a triangle, operations as a rectangle and resources as a circle.

Modeling - Manufacturing operation

Putting it all together

Combining all of the above building blocks we can construct a network representing the complete supply chain from end to end.

The picture below shows a simple network with 3 levels.


Drawing this type of schematic network of your environment is extremely useful before you start entering data in frePPLe. It will help you in getting the data ready for the next steps of this wizard.

Modeling - putting it together

Once you will have populate your data in frePPLe, you can verify the correctness of your model by visualizing the network you have defined. This is done with the Supply Path / Where Used report.

You can try to look at the supply path of some sales orders in any of the demo models:

  • Open the sales order list from the menu “sales / sales orders”

  • Select any sales order from the list by clicking on the triangle next to its name.

  • Select “supply path” from the available tabs.