Hello,
We are in the process of implementing a new NAV 2013 system, moving on from a different ERP system.
One area that we can't get working reliably is MRP.
The results we are obtaining from the production planning worksheet (regenerative plan) are unusable. We don't use forecasts - our inventory control is based on setting reorder points against relevant items. We set the 'Minimum Order Quantity' field using our economical batch quantity for each item. Our items generally have BOM & Routing, and may have multiple levels.
Scenario 1 - 'Lot-for-Lot' reorder policy
If we set all items to 'Lot-for-Lot' reordering policy, & set our reorder point using the 'Safety Stock Quantity' field (as the 'Reorder Point' field is not used with this method), then the planning worksheet produces a reliable suggested order list in terms of order quantities, but because most order suggestions are triggered by inventory falling below the safety stock level*, the suggestions are mostly flagged as an 'Exception', and the due date is set to today, regardless of whether we have raw material or sub-components in stock. Order suggestions for raw material and sub-assembly components are then scheduled backwards, so e.g. NAV tells us that we should have purchased a component 6 weeks ago.
We have been unable to change this behaviour, so the dates being suggested by NAV are useless - we need to know when we can actually make the items, planning forwards, not looking backwards!
* e.g. An item has safety stock = 100, inventory = 110, and we ship a sales order for 20. We still have 90 in stock, which is sufficient until we can make some more in 6 weeks time, but NAV flags an 'exception' in the planning worksheet and sets the due date to today.
Scenario 2 - 'Fixed Reorder Qty.' reorder policy
If we set all items to 'Fixed Reorder Qty. reorder policy, NAV requires entry of a 'Reorder Quantity' against each item - we cannot leave it as zero.
We can set the 'Reorder Point' field with this policy, so 'Safety Stock' is set to zero. The results of the planning worksheet's date suggestions are generally OK (unless an item falls below the safety stock qty., even though it is set to zero), and the quantity calculations for genuine demand are also generally OK. However, instead of maintaining stock at our reorder point, NAV wants to keep stock above our reorder point (even if reorder point = 0); so NAV suggests that we order every item on our system. Even if the reorder point is set to zero, and there are no commitments for an item, NAV suggests that we order 1, because we have set the 'Reorder Quantity' field to 1 (because NAV won't allow us to leave it set to zero!).
We therefore end up with a ridiculously long list of nonsense suggestions to order items that we don't actually need.
Has anyone else experienced similar problems using either of 'Lot-for-Lot' or 'Fixed Reorder Qty.' reorder policies?
Are there any solutions available? I don't mind if we have a solution based on 'Lot-for'Lot' or 'Fixed Reorder Qty.' as long as it works.
Any help would be gratefully received!
Thank you.
Mark Woodward
