Purchase order lead time is the time interval that occurs between placing a purchase order for the item with a vendor and eventually receiving that item into a warehouse. Sales forecast, purchase order lead time and safety stock among other components help to figure out the reorder point for an item in inventory. Thus, the purchase order lead time plays the important part in determining what the reorder point should be. That in turn directly impacts the Dynamics AX MRP to decipher the important question – WHEN to place an order.
Purchase Lead Time Hierarchy
In the Dynamics AX, master scheduling searches for this purchase order lead time for an item from three different places following a particular priority. At first, the Dynamics AX MRP gives the most significance to the Item coverage. Going to the Released Products in an AX > Plan ribbon bar > Coverage group > Item coverage button will open up the form in the Overview tab by default. The Purchase time field can be found on a Lead Time tab under the Purchase section.
The second place in AX where Microsoft Dynamics AX MRP looks at, in order of the priority, for purchase order lead time is in the “Site specific order settings” form. Going to the Released Products in an AX > “Plan” ribbon bar > “Order Settings” group > “Site specific order settings” button, will open up the “Site specific order settings” form. The purchase order lead time is located under the Purchase order fast tab, and Other section.
Lastly, the Dynamics AX MRP looks at, in order of priority, for purchase order lead time is in the “Default order settings” form found in Released Products in AX > Plan ribbon bar > Order the Settings group > the Default order settings button. The purchase order lead time appears under a Purchase order fast tab, Other section.
Default Vendor Dependency
Now, if a purchase order lead time is found in either of these three places, it can still be overridden if there are an existing vendor trade agreement journals for a designated item. Then the purchase order lead time from the vendor trade agreement will trump all other values found elsewhere in the Dynamics AX.
This rule will hold true, except for 2 conditions. The 1st condition is that no default vendor has been assigned to the item, and that could be verified in two different setups in AX.
The primary spot is on the Released Products in an AX > “Plan” ribbon bar > “Coverage” group > “Item coverage” button. Proceed to the “General” tab and the Vendor account field can be found under a “Use Specific Settings”. If the “Use specific settings” checkbox is selected and Vendor account selected, then that vendor will be considered as the default vendor by Dynamics AX MRP.
Secondly, the MRP looks for default vendor in the Released Products in AX on the item details form on the “Purchase” fast tab under the “Administration” group. This tells the user whether there is the default vendor assigned to an item.
Additionally, when the purchase lead time from the Vendor Trade Agreement journal is used whenever the “Find trade agreements” is turned ON in the “Master planning parameters” form, in the “Planned orders” tab.
Important to note:
1. If there a default vendor set up does exist for an item, MRP will not take into account the purchase order lead time from the active vendor trade agreement journal.
2. MRP will follow priority for the lead time accordingly: item coverage form, site specific order settings form and default order settings form.
Even though the navigational path might be different, the core concept about the MRP and purchase order lead time behavior are the same in both Microsoft Dynamics AX 2012 and Microsoft Dynamics AX 2009.