My Fragrance Supplier Takes Two Weeks to Deliver — How Do I Calculate Reorder Points Separately for Fast- and Slow-Selling Candle Fragrances?

Four scents, four speeds

The example uses four scents at four speeds, from a fast seller at 240 candles a month to a very slow one at 10. They are real CSI oils chosen to show different price tiers and pack shapes; use your own list and your own sales. The candle is 150 g at an 8% load, so each holds 12 g of oil, and a 3% allowance for pour loss and test burns brings that to 12.36 g per candle. The two-week delivery is the reader's own figure; CSI does not publish delivery times.

The fast scent uses 24 times as much oil a day as the very slow one. If the lead time were the only thing that mattered, the reorder points would be in the same ratio. They are not, and the reason is the buffer.

The reorder point for each

Every reorder point is the oil used during the delivery plus a buffer. The delivery part is simple: 14 × oil a day. For the buffer, this page uses a rule with two halves: 7 days of that scent's sales, or one 10-candle order, whichever is bigger. The 10-candle order is an example; use the largest single order you have actually had for each scent, such as a gift hamper or a café refill.

The fast and medium scents come out at 21 days of sales each: 14 for the delivery and 7 for the buffer. The slow scent's buffer is set by the 10-candle order rather than by a week of sales, so it reorders at 24.0 days. The very slow scent reorders at 44.0 days, more than a month of its average sales. In grams, the spread is 2.08 kg down to 181.28 g, a ratio of about 11 to 1, not the 24 to 1 you would get from speed alone.

Why slow scents need a different buffer

A scent that sells 10 candles a month does not sell a third of a candle every day. It sells nothing for a week, then four in one order, then one, then nothing again. Its average is a smooth line; its reality is lumpy. A buffer built from days of the average protects the smooth line and fails the lumpy reality. That is why, for slow scents, the buffer is better sized from the orders themselves. If the scent sometimes goes out in a hamper of 10, the shelf needs 10 candles' worth on top of the delivery wait.

With a flat 7-day buffer, the very slow scent would reorder at 86.52 g, seven candles' worth. A single 10-candle order would take the shelf to zero with the new bottle still a fortnight away. The larger-of rule adds only 94.76 g to that scent, well under one 100 g bottle, and removes the risk. The fast scent is unchanged, because a week of its sales (56 candles) is already bigger than any single order.

One week against two

A two-week delivery costs you stock on every scent, but not equally. Each reorder point grows by exactly seven days of that scent's oil. For the fast scent that is a lot of oil; for the slow scents it is a few grams. The table shows the same scents with a 7-day delivery and a 14-day delivery.

Almost all of the extra stock a two-week lead demands sits on the fast scents: 692.16 g of the fast scent against 28.84 g of the very slow one. If you ever have a choice of supplier or dispatch speed per scent, the fast sellers are where a shorter lead saves the most. If your supplier's lead varies, record it per order and use the slowest in the maths. The bestseller trigger page shows the same effect for leads from 3 to 21 days.

How much to order for each

The reorder point tells you when. How much depends on the scent's speed and the pack sizes. Fast and medium scents order a month at a time in kilos where that is cheaper. The slow scent orders a month in 100 g bottles. The very slow scent orders two months, because one month is only a little over 100 g and ordering it monthly would mean paperwork for a single bottle. All figures use in-stock bottles of 50 g and above.

Look at the last column. Eucalyptus Spearmint is ₹3.54 a gram at 100 g and ₹3.07 at 1 kg, a 13.3% saving, so the fast scent belongs in kilos on price as well as convenience. Santal Noir is ₹9.19 at 100 g and ₹9.12 at 1 kg, less than 1% apart, so its 100 g bottles cost almost nothing extra and keep far less oil on the shelf. Raat Ki Rani is ₹7.00 at 100 g and ₹6.77 at 1 kg; for 10 candles a month, a kilo would last 243 days. Buying a kilo of a very slow scent is not a saving; it is two years of stock.

Running it without a spreadsheet

The arithmetic only has to be done once per scent per quarter. After that, the reorder points can live on the shelf as bottle counts.

A few neighbouring pages go further. For a new scent with no sales history at all, the new-fragrance page covers the first buy. For one bestseller and its exact kilogram trigger, see My Bestseller Sells 300 Units a Month and Uses 16 g of Fragrance per Candle — How Many Kilograms of Fragrance Should Trigger My Reorder?. If your wax supplier has its own long lead, the 10-day wax lead page sets that reorder level and explains why orders in transit must be counted. And for the full model behind all of these, the procurement model page puts sales, consumption, lead time, wastage and safety stock into one sheet.

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