A supplier promises 14 days. Your item coverage is set to 14 days. But the last five deliveries took 21 days. That gap — between planned and actual lead time — is one of the most common and least visible causes of stockouts. The Lead Time Advisor in ForgeStock makes it visible.

What the Lead Time Advisor does

The advisor analyses your open purchase order lines and compares:

• Planned lead time — the lead time configured in item coverage or default order settings in D365FO

• Historical average lead time — calculated from fully invoiced purchase orders for the same item and vendor over the past 12 months

• Variance — the gap between the two, in days

Lines where actual lead time consistently exceeds planned lead time are flagged, so your procurement team can act before a late delivery becomes a stockout.

Before you start

The historical average lead time is only as good as your purchase order history. The advisor requires fully invoiced purchase orders for the item-vendor pair within the lookback period. New vendors or new items with no invoice history will show 0 for historical average — this is expected and not an error.

Step 1: Run the batch job

In D365FO, go to: Inventory management → Periodic tasks → Inventory Optimizer → Run Lead Time Advisor

Parameters:

• Site — select the site to analyse

• Lookback period (months) — default is 12 months. Reduce to 6 months if you want to focus on recent supplier performance only

• Include ABC classes — recommended to include all classes on first run

Click OK to run. The job reads open purchase order lines and invoiced purchase history, then populates the advisor results.

Step 2: Open the advisor

Navigate to: Inventory management → Inquiries and reports → Inventory Optimizer → Lead Time Advisor

If the form is empty after the job has run, confirm that open purchase order lines exist for stocked items with a remaining open quantity greater than zero. Category or service lines without an item number are excluded by design.

Step 3: Read the results

The grid shows one row per open purchase order line. Key columns:

• Item number / Item name — the purchased item

• Vendor account / Vendor name — the supplier

• Promised delivery date — the date on the PO line

• Planned lead time (days) — from item coverage or default order settings

• Historical average lead time (days) — derived from invoiced PO history

• Variance (days) — historical average minus planned lead time. Positive means the supplier is consistently slower than planned.

• ABC/XYZ class — so you know the item's planning priority

Step 4: Prioritise by variance

Sort by Variance descending to see which item-vendor combinations have the largest gap between planned and actual lead time.

Focus first on:

• High variance items in ABC class A or B — these carry the most stockout risk

• Lines where the promised delivery date is already past — these are overdue and need immediate follow-up

Step 5: Take action

The Lead Time Advisor is a diagnostic tool — it surfaces the problem, and your procurement team takes action. Typical responses:

Update item coverage lead time — if a supplier is consistently delivering in 21 days instead of 14, update the planned lead time in item coverage to reflect reality. This feeds directly into the Safety Stock & ROP Simulator and improves your reorder point calculations.

Go to: Master planning → Setup → Coverage → Item coverage → find the item → update Lead time (purchase).

Contact the supplier — use the variance data as evidence when discussing delivery performance. A positive variance of 7+ days on an A item is a strong case for a supplier review meeting.

Expedite open orders — for lines where the promised date has passed, contact the supplier immediately and flag the line in the MRP Exception Advisor for follow-up.

Step 6: Feed results into the Safety Stock Simulator

The Lead Time Advisor stores historical average lead times in the system. When you next run the Safety Stock & ROP Simulator, ForgeStock uses these historical averages as the lead time source — giving you more accurate safety stock calculations than relying on planned lead time alone.

This is the key connection between the two tools: better lead time data → better safety stock → fewer stockouts.

How often should you run it?

• Weekly for A items with known supplier performance issues

• Monthly as part of your standard procurement review

• After any supplier change — new vendor, new contract, or new item-vendor assignment

Tips

• If planned lead time shows 0 for most items, set up Lead time (purchase) in item coverage or default order settings — the simulator cannot calculate meaningful reorder points without it

• Items showing 0 for historical average are not a problem — they simply have no invoiced history yet. Monitor them manually until enough history builds up.

• Use the vendor filter to pull all lines for a specific supplier before a performance review meeting — instant data, no manual reporting needed