We use a simple but effective system. 1. Every consumable part/chemical is on a shelf that’s labeled and directly corresponds to a pick list. 2. Every Friday truck inventory is done by each lead tech assigned to that vehicle using the pick list. They refill anything that was consumed or needs repair (quick connectors, brushes, o-rings etc..) I like Google Sheets converted to a PDF. See one of mine attached 3. Every Monday the shop manager (or a lead tech) reviews the list to see what was used and places an order if needed. 4. Each bin/part/chemical has a min and max amount on the label. If the item falls below that amount that triggers a re-order of that part. 5. Every part is listed in a catalog showing where to purchase that item. (This is reviewed quarterly to make sure we’re getting the best pricing) 6. Weekly orders are approved by ops manager to make sure there are no resources being wasted. Hope this helps!