The formula
Par level = Daily usage x (Lead time days + Order cycle days + Safety days)
Reorder point = Daily usage x Lead time days
Order quantity = Par level – Stock on hand
Each piece earns its place. Lead time covers what you use while the truck is on its way. The order cycle covers what you use before you can order again. Safety days absorb the gap between average usage and a real weekend. Miss out the order cycle, the most common error, and the par lasts only until the next order is placed, not until it arrives.
The reorder point is the trigger, not the target. When stock falls to what lead time alone consumes, ordering today means the delivery lands as the last of the old stock is used.
How to use it, with an example
- Pick one item and get its average daily usage from a week or two of counts and sales, not from memory.
- Enter the supplier’s honest lead time in days, and how often you order the item.
- Set safety days by supplier reliability and item importance: one day is a sane default, two for the protein you cannot 86.
- Enter what you counted on hand, and read today’s order quantity straight off the result.
- Repeat for your top ten money items first. Pars for everything can come later; pars for what matters cannot.
Worked example: A kitchen uses 12 lb of chicken breast a day. The supplier takes 2 days, orders go in every 3 days, and the chef keeps 1 safety day. Par is 12 x (2 + 3 + 1) = 72 lb, the reorder point is 12 x 2 = 24 lb, and with 30 lb counted on hand the order today is 72 – 30 = 42 lb. Weekly usage of 84 lb tells purchasing what the commitment looks like across a month. The calculator above is prefilled with these numbers.
Pars only work if usage and stock stay current, which is why restaurants outgrow the clipboard version. In Odoo for Restaurants, usage flows from sales and stock from the Odoo Inventory module, while the buying itself runs through the Odoo Purchase module, so reorder warnings fire from live numbers instead of from whoever walked past the shelf last.
Common mistakes
- Leaving the order cycle out of the par. A par built on lead time plus safety alone runs dry mid-cycle, every cycle. The kitchen then emergency orders, which trains everyone to ignore the par and order by feel again.
- Setting usage from the busiest day. Pars built on Saturday usage overstock Monday to Thursday, and perishables pay for it. Safety days are the cushion for spikes; the base rate should be the average day, a point restaurant inventory management tips makes about count discipline generally.
- Never reviewing pars. Menus change, seasons change, a dish gets popular. A par set in January is a rumor by June. Review pars whenever the menu changes and at least quarterly for your top value items.
- One safety rule for everything. Rice can ride a late truck; fresh fish cannot. Safety days should follow shelf life and substitutability, not a house-wide habit.
- Ordering to par without counting. The formula’s last input is stock on hand, and guessing it undoes the rest. A two minute count of the item beats a perfect par calculated against an imaginary shelf.
- Pars for everything, maintained for nothing. Two hundred stale pars are worse than twenty live ones. Cover the high value, high pain items properly, and let cheap dry goods run on simple minimums.
FAQs
What is a par level in a restaurant?
The amount of an item that should be on your shelf when a delivery arrives, set so you can serve until the next delivery plus a safety cushion. Staff order up to par: count what is there, subtract from par, and the difference is the order.
What is the difference between par level and reorder point?
Par is the target you stock up to; the reorder point is the level that triggers an order. The reorder point only covers lead time. Confusing the two either doubles your stock or empties your shelf early.
How much safety stock should a restaurant keep?
For most items, half a day to two days of usage, scaled by supplier reliability and shelf life. Volatile fresh items bought from a shaky supplier sit at the top of that range; shelf stable goods from a daily supplier need almost none. Safety stock is insurance, and like insurance it should be priced per risk.
How often should par levels be reviewed?
Whenever the menu changes, when a supplier or lead time changes, and at least quarterly for high value items. Usage drift is silent: a dish that picks up pace empties the shelf before anyone updates the sheet, and the first symptom is an 86 on a Friday.
Should every item have a par level?
No. Pars pay off on high value, high usage and high pain items: proteins, dairy, fresh produce, core alcohol lines. For cheap dry goods, a simple minimum and a visual check do the job.
What if my usage swings wildly by day of week?
Use the weekly average for the base rate, and let safety days absorb the weekend. If one item truly lives two lives, weekday prep and weekend service, some kitchens carry a second, weekend par for it. That is still arithmetic, just with two numbers instead of one.
