How do you automate purchasing in Business Central?

Lancaster Agentic is a purchasing agent for Microsoft Dynamics 365 Business Central: it reads your sales history, stock on hand, open purchase orders, vendors and lead times, then tells you what to order and how much. You ask in ChatGPT or Claude, review a reorder workbook, and it creates purchase orders in Business Central when you tell it to.

What does Lancaster Agentic read from Business Central?

Lancaster Agentic reads five things: sales history, stock on hand, open purchase orders, vendors and lead times. It syncs them into one common shape, so the same purchasing logic runs the same way whichever ERP the data came from.

Sales history goes back three years. Open purchase orders count as incoming supply, so Lancaster Agentic does not suggest buying what is already on its way. The hosted engine reads your data with read-only access. A purchase order is created in Business Central only when you tell it to create one.

How does Lancaster Agentic decide what and how much to order?

For each item, Lancaster Agentic forecasts demand, then orders enough to cover the vendor lead time plus your safety stock, measured in days of cover. Stock on hand and open purchase orders are counted first, so it only suggests the gap.

• Forecast. The default method looks at 36 months of monthly demand for each item. Items that sell most months get a trailing average (12 months by default). Items that sell only now and then get a method built for intermittent demand, and their reserve is at least one typical order.
• Seasonal options. If you want seasonality, you can choose a same-season-last-year or three-year seasonal median method. The default is a flat rate, not seasonal.
• Lead time. A one-run override wins, then a vendor and warehouse rule, then a vendor rule, then the lead time stored in your ERP.
• Safety stock. Set as days of cover, with a company default you can change.

Every row in the workbook says which forecast method it used and why, so a buyer can check the reasoning instead of trusting a black box.

What is in the reorder workbook?

The workbook is a spreadsheet you download and review before anything is ordered. Its main sheet, Order Recommendations, lists each item with the numbers a buyer needs to decide.

Each row shows figures such as available stock, quantity on order, the sales forecast, safety stock, the suggested order quantity, lead time, the forecast method and the primary vendor. Summary cells show inventory value and overstock value. Other sheets cover incoming purchase orders, product folders and the forecast methods. If an item has no lead time, the lead time cell is left blank and marked red so you can fix it at the source.

How do purchase orders get created in Business Central?

You review the suggested lines for a vendor, then tell Lancaster Agentic to create the PO, and it is created in Business Central.

Nothing goes to a vendor until someone on your team sends it. Lancaster Agentic saves the purchase order in your ERP; your buyers still decide when and how it reaches the vendor.

Where do you use it: ChatGPT, Claude or Slack?

For Business Central, you use Lancaster Agentic in ChatGPT or Claude. You ask plain questions such as "What should I reorder from Ironwell Tools this week?" and get the answer and the workbook, then the PO when you ask for it, in the same conversation. See the purchasing agent in ChatGPT and Claude.

Slack works with EBMS only today. If your team lives in Slack and runs Business Central, book a call and tell us; we will not claim Slack support for Business Central until it exists. Lancaster Agentic is coming to the ChatGPT Plugin directory; today we set it up with you.

How does it work alongside Business Central planning and requisition worksheets?

Business Central has its own supply planning. You set a reordering policy on each item or stockkeeping unit (Fixed Reorder Qty., Maximum Qty., Order or Lot-for-Lot), then run Calculate Plan in the requisition worksheet to get action messages and turn them into purchase orders. Microsoft describes the requisition worksheet as the main planning page for wholesale companies that replenish by purchase or transfer.

That planning engine works from the parameters you set and the demand it can see: sales orders, demand forecasts you enter, blanket orders, safety stock and reorder points. Lancaster Agentic starts from a different place: it builds a forecast from your sales history and turns it into a purchase list you can question in plain language. Teams can use both. Some keep Business Central planning for items with well-tuned policies and use Lancaster Agentic as a forecast-based check before they buy. For the full trade-off, read Business Central planning vs Lancaster Agentic. To tune the built-in fields first, follow our guide on setting reorder points in Business Central.

What is the status of the Business Central connection, and how do you get it?

The Business Central connection is built and tested against Business Central test systems; we connect it to yours with you during setup. Testing covered the data sync, reorder lists for several vendors, a hand check of item numbers and a test purchase order that was created and then deleted.

To get started, book a call. We walk through how it works and then connect your Business Central company with you during setup.

Frequently asked questions

Does Lancaster Agentic send purchase orders to my vendors?

No. Lancaster Agentic creates the purchase order in Business Central. Nothing goes to a vendor until someone on your team sends it.

Can Lancaster Agentic create a purchase order without me asking?

No. It creates a purchase order in Business Central only when you tell it to.

Do I have to use the requisition worksheet to use Lancaster Agentic?

No. Lancaster Agentic builds its own forecast from your sales history, stock, open purchase orders, vendors and lead times. You can keep using Business Central planning alongside it.

Does Lancaster Agentic work in Slack for Business Central?

Not today. Slack works with EBMS only. Business Central customers use Lancaster Agentic in ChatGPT or Claude.

Is Lancaster Agentic already used by Business Central customers?

The connection is built and tested against Business Central test systems. We connect it to your company with you during setup, after you book a call.

Sources

1. About planning functionality, Microsoft Learn, accessed 2026-10-01
2. Supply Planning, Microsoft Learn, accessed 2026-10-01
3. Setup best practices - Reordering policies, Microsoft Learn, accessed 2026-10-01