Inventory tracking is how you catch food cost drift before it eats your margin. The basic loop runs weekly: count what is on hand Sunday night, add the week invoices, subtract Sunday count, and you have weekly COGS. Divide by sales to get food cost percentage. For a small truck a Google Sheet works for the first six months — columns: item, unit, par, on-hand count, last invoice cost, extended value. Total it and compare to target (28-35% benchmark). When you outgrow the spreadsheet, MarketMan and MarginEdge integrate with major POS systems and pull invoices from suppliers automatically; $50-$200/month. Daily prep sheets are the second leg. Investigate any week where actual food cost is more than 2-3 points off target. Causes: theft, over-portioning, spoilage, supplier price hike, recipe creep.
- Counting "by feel" instead of with a scale and sheet.
- Never reconciling invoices against deliveries — vendor short-shipments are real.
- Letting one cook portion freehand; a $0.50 protein over-pour 100 times a day is $1,500/month.