Pricelist Hierarchy for BTO Suggestions

I was wondering if anyone had more information on the hierarchy of supplier pricelists transferring to suggestions/PO.s. While this is only one particular instance, pricelist hierarchy does come up in conversation at our company on occasion.

We have a BTO part that we purchase from 1 primary supplier. However, earlier this year, we had to purchase it from a different supplier due to availability and minimums. It was a one-time solution for that particular order. The pricelist for the alternate supplier was entered with an expiry date (we use 30 days as a default), and that has long since expired. Demand for this part did not come up again until after this pricelist expired, and we’ve since been adding current pricelists for our primary supplier of that product.

However, it came up in review that the last two times we purchased this product after that one-time solution were suggested and purchased from the alternate supplier.

It was our understanding that purchasing suggestions run on the pricelist expiry dates and will default to the earliest non-expired pricelist, but how much bearing does the last-purchased-from supplier have on purchasing suggestions when a supplier is not specified in the Buy to Order field on the Releases Tab in Sales Order Entry? The only pricelist for the alternate supplier had long been expired, and there had been current non-expired pricelists for our primary supplier active at the time of those purchases.

While we try to reiterate that it’s best practice to specify the intended supplier in the BTO field to avoid situations like these (since we have multiple suppliers for other parts), it is not always practiced during Sales Order Entry.