I'm Growing Quickly and Keep Running Out of Soy Wax — How Do I Set a Reorder Point Using Monthly Consumption and Supplier Lead Time?

Reorder point = daily use × real lead time + safety stock — recalculated every month

A reorder point is the stock level at which you place the next order, so that the new wax arrives just as the old wax reaches your safety stock. The formula is short: ROP = daily use × lead time + safety stock. Three things go wrong for a growing maker, and each one makes you run out. Daily use is taken from an average of past months, which is always too low when you are growing. Lead time is taken as the supplier's delivery time alone, forgetting the day you take to notice and order and the day you take to check the delivery. And safety stock is either zero or a guess that never changes.

Here is the worked example on this page. A maker's wax use over six months — an example you replace with your own records — went Apr 14 kg, May 17 kg, Jun 19 kg, Jul 24 kg, Aug 28 kg, Sep 33 kg. That is growth of about 18.7% a month. Projected forward, October needs about 39.2 kg, or 1.31 kg a day (6.8 candles of 200 g). The supplier lead time is the reader's one week; add one day to notice and place the order and one day to check the delivery, and the real lead time is 9 days. Lead-time demand is 1.31 × 9 = 11.8 kg. Add 5 days of safety stock (6.5 kg, an example cover you set) and the reorder point is 18.3 kg.

Rounded to whole bags, that is 20 kg: keep 2 sealed 10 kg bags of CSI 468 on a separate shelf labelled REORDER. The day you cut open the first of them, you place the next order. No spreadsheet check is needed on the production floor; the bag is the signal. And at the start of every month, recalculate the number from the new forecast — at this growth rate it rises to 21.7 kg in November and 25.8 kg in December.

Why growing makers keep running out: the trailing-average trap

Most makers who run out did set a reorder point. It was simply built on the wrong number. Suppose you used the average of the last three months — 24, 28, 33 kg, an average of 28.3 kg a month or 0.94 kg a day — and took the lead time as nine days with no safety stock. Your reorder point would be 8.5 kg. But in October you are actually using 1.31 kg a day, so over the nine-day lead time you need 11.8 kg. You run short by 3.3 kg — about 17 candles you cannot pour — before the order lands.

The middle row is the subtler mistake. If you count only the supplier's seven days, the two internal days — noticing and checking — come out of your safety stock every single cycle. Your buffer is then 3.9 kg in practice, not 6.5 kg. Write down how long your side takes, honestly. If orders sit in a WhatsApp chat for two days before anyone confirms them, your lead time is two days longer than the supplier's.

The monthly reorder worksheet

Here is the whole calculation as a worksheet you can copy. Each month uses the trend forecast only — it does not include a festive spike. If November will carry Diwali orders on top of the trend, add them to that month's forecast before you compute the reorder point; the Diwali 300 kg plan does exactly that.

The order size in this worksheet is simply next month's forecast rounded up to whole 10 kg bags — 40 kg in October. That keeps one month of cover arriving at a time, which suits a business whose volume is still finding its level. Larger, less frequent orders are a separate decision with their own cash maths; whether 100 kg a month should be bought monthly, fortnightly or in bulk and 25 kg today versus 100 kg at a discount cover it.

What running out actually costs — and what the buffer costs

Put both sides in rupees. The 6.5 kg of safety stock in CSI 468 is worth ₹4,158.91 at the 10 kg rate — money that sits on the shelf permanently. Against that, every day without wax is a day without 6.8 candles. At ₹271.38 of materials per 200 g Japanese Cherry Blossom candle (wax, oil, wick and jar; excluding labour, packaging, freight and GST), that is ₹1,834.17 of production a day that does not happen — and the margin on those candles, the customers who wait, and the ones who do not.

There is a hidden cost too. Makers who run out rarely stop production; they buy whatever wax is available locally and pour it into the same jars with the same wick. That is an untested raw-material change made under pressure, and it is the most common route to a batch of tunnelling or sweating candles. The cheapest insurance is not a bigger pile of your main wax. It is an approved backup wax, tested now, while you have time.

Qualify a backup wax now: 4 control + 4 backup candles

The test is the standard control comparison used throughout this series. Your main wax is the control; the backup is the candidate. Both are poured the same day, with the same oil lot, wick and jar, and burned side by side. Four of each — three burned, one kept on the shelf — is a labelled working minimum. In this example the main wax is Premium Coconut Soy Wax CSI 468 and the backup is Luxury Soy Wax Chunks. CSI's product pages state up to 13% fragrance load for both; CSI 468's page also gives a 50–53°C melting point and 58–60°C pour temperature, and the Chunks page gives 80–90°C for fragrance addition and 75–80°C for pouring in its spec table. Those are the makers' figures — they do not tell you which wax suits your wick.

The kit costs ₹2,135.00 — about 1.2 days of lost production materials at October's rate. Notice the backup-wax line: 772.8 g of Chunks is cheapest as two 500 g bags (₹598.00), because Chunks are listed at ₹598.00 a kilo in 500 g bags and ₹599.00 in the 1 kg bag. For per-candle comparison at production packs, a 200 g Japanese Cherry Blossom candle costs ₹271.38 in CSI 468 (10 kg rate) and ₹264.39 in Chunks (5 kg rate). That difference is the price of the backup if you ever need it — not a reason to switch.

The decision rule: set it, label it, reset it monthly

For this maker, the concrete actions today — 1 October — are: put 2 sealed 10 kg bags of CSI 468 on the REORDER shelf; place October's order of 4 × 10 kg of Premium Coconut Soy Wax CSI 468 (₹25,480.00); and pour the backup test this week so the result is on file before the festive peak. If your own history shows no growth, the same routine works — the reorder point just stops moving.

Related inventory questions in this cluster

This page sets a reorder point for steadily growing use. Safety stock for a 30–80 kg swing handles volatile use with a statistical buffer; the Diwali 300 kg plan adds a dated festive spike; when to manage wax as commercial inventory and the procurement-system capstone pull reorder points, safety stock and pack sizes into one system. For a fixed one-week lead time at steady volume, see 50 kg a month with a one-week supplier.

Frequently asked questions