Menu engineering

A high food-cost percentage isn't the whole story. An item at 34% food cost that sells 400 a week out-earns a 22% item that sells 12 — but per-item margin alone never shows that, because it's never multiplied by how many you sell. The Menu tab in Reports does that multiplication, so you can see which dishes actually pay the bills.

How does Rinvy decide if a dish is a Star or a Dog?

Rinvy compares each item's share of units sold with 70% of an equal share, and its margin per sale with the menu's average margin. Michael Kasavana and Donald Smith built this matrix at Michigan State University around 1982. In his own introduction to menu engineering, Kasavana calls the belief that food cost drives profit "perhaps the oldest misconception in food service management".

The two axes, over the period you pick:

• Popularity — the item's share of all units sold (its menu mix), measured against 70% of an equal share. If you had 10 items and each sold the same amount, each would hold 10%; an item is "popular" once it clears 70% of that fair share.
• Profitability — the item's contribution margin per unit (selling price − food cost), measured against the average across everything you sold.

The equal share counts only the items that sold in the period. With 20 items on the menu and 16 that sold, the popularity bar is 70% of 1/16, about 4.4% of units. The average margin is weighted by units: total contribution divided by total units sold, so a dish that sells a lot pulls the average toward its own margin. An active item that sold nothing still appears, at zero units. It can never count as popular, so it lands as a Puzzle or a Dog, and it moves neither line.

Crossing the two gives four groups:

• Star — popular and profitable. Your winners; protect them and feature them.
• Plowhorse — popular but below-average margin. People love it, but it earns thin — re-cost the recipe or nudge the price.
• Puzzle — high margin but unpopular. It earns well on each sale but rarely sells — promote it, move it up the menu, or rename it.
• Dog — unpopular and low margin. A candidate to rework or retire.

Before you raise a Plowhorse's price, look at how menu prices around you are moving. USDA's Economic Research Service tracks restaurant prices ("food away from home") apart from grocery prices in its Food Price Outlook.

Burger vs. tuna, in numbers

Say a burger sells for $16.00 with a food cost of $5.40 (34%), and a seared tuna plate sells for $28.00 with a food cost of $6.10 (22%). The tuna earns $21.90 per sale and the burger $10.60. Over a week, the burger sells 400 and contributes $4,240.00. The tuna sells 12 and contributes $262.80. The tuna is a likely Puzzle. The burger is a Star or a Plowhorse, depending on the menu's average margin.

Reading the tab

The scatter plots every item by units sold (across) and contribution per unit (up), with the bubble sized by revenue and dashed lines marking the two averages, so each item falls into one of the four corners. Below it, the table lists every item sorted by total contribution dollars — revenue minus food cost over the period — which is the number that tells you what a dish is worth to the kitchen, not just its percentage.

1. Use the date range at the top. Menu engineering defaults to the last 30 days, so menu-mix shares have enough sales behind them to mean something.

2. Plowhorses and Puzzles are where the money is. A Plowhorse is a pricing or portioning fix; a Puzzle is a merchandising fix.

3. The top rows are the dishes carrying your menu. Tap any row to open its full menu item report.

Combos count as their own item here — a bundle has its own price and its cost is the sum of its components — because menu engineering rates what the customer actually buys and pays for. Archived items still appear if they sold in the period, labeled so you can tell them apart.

Where the numbers come from

Food cost per sale is the same figure the rest of the app uses — weighted-average receipt cost, recipe-exploded, portion-scaled — see cost and pricing. Units sold come from your uploaded sales. Contribution is revenue minus food cost; nothing here fires an alert or changes your data.

Revenue on this tab is the menu price in Rinvy times units sold, not the dollar total from your POS. Discounts and comps don't lower it, and a price change applies to every unit in the period. A * next to Margin per sale means the cost is priced from product defaults, not receipts, and a Cost incomplete tag means an ingredient could not be costed.

On the Menu page, each item that sold in the last 30 days shows its contribution and quadrant next to its price, so you can see a dish's standing without opening Reports.