I noticed that the inventory levels of our vendor were dropping, but we weren't buying. Meaning our customer was ordering the same product from a competitor.
I proposed that we spend the money to buy the rest of the material at the vendor. Basically denying our competitor the materials and forcing either them to come to us or the customer dropping the order and reordering through us. This would have been a risk because that's about a year supply of proprietary castings that we can't use for anything else, but I really thought it was a worthwhile opportunity. But it went against lean principles so we didn't do it.
Fast forward 6 months and our competitor basically did the same thing to us.