I Use 50 Kg of Soy Wax per Month — How Much Safety Stock Should I Keep If My Supplier Normally Takes One Week to Deliver?

The short answer: one 10 kg bag, and the reason is the word "normally"

At 50 kg a month you use 1.667 kg of wax a day — about 9.1 candles of 200 g at an 8% load. In the seven days between ordering and receiving, you will pour 11.67 kg. That is lead-time demand, and it is not safety stock: it is the wax you will certainly use while you wait. If the delivery always took exactly seven days and you always used exactly 1.667 kg a day, a reorder point of 11.67 kg would land every order on an empty shelf, perfectly on time. Nobody runs a workshop like that.

Safety stock exists for the two things that wobble: how long the delivery takes and how fast you use wax while you wait. Your title already contains the clue — "normally" one week. Three reasonable ways to size it are worked below, and at your volume they land between about 6 and 14 kg. Rounded to a real bag you can keep sealed, the practical answer is 10 kg — six days of normal use — giving a reorder point of 11.67 + 10 = 21.67 kg.

CSI does not publish delivery times, so every lead time on this page is either your own figure or a labelled example. The seven days is yours; the twelve-day worst case and the variation figures used in the calculations are examples you should replace with numbers from your own order log. The method stays the same whatever the numbers are.

Three ways to size safety stock at 50 kg a month

There is no single correct formula. Small manufacturers commonly use one of three approaches, from simplest to most data-hungry. Use the one your records can support, and check the answer against the others.

Method 1 is honest about being a judgement: you choose how many days of surprise you want to survive. Method 2 is the most cautious, because it assumes your slowest delivery arrives in your busiest week. Method 3 needs at least a few months of records, but it shows something the other two hide: with these example inputs, 82% of the risk comes from the delivery time, not from your daily usage. If you only allowed for usage wobble, the safety stock would be 2.62 kg. Allowing for a delivery that can drift by two days lifts it to 6.09 kg.

That is why the word "normally" matters. A supplier who is reliably slow is easier to plan around than one who is usually fast and occasionally very late. Log the real lead time of every order — order date, payment date, arrival date — and after six orders you will know which kind you have. Setting a reorder point when you keep running out uses that log to move the trigger as you grow, and safety stock when monthly use swings from 30 to 80 kg handles the case where usage, not delivery, is the wobble.

The reorder point and the order that follows it

With a 10 kg safety bag, your reorder point is 21.67 kg. In practice that means: when the open stock plus the unopened bags (not counting the sealed safety bag) falls to about 12 kg, place the order. The order itself should be one month of use, 50 kg, which on CSI's list can be bought in one of two ways for Natural Soy Pearl — a single 50 kg bag (₹21,240.00, listed in limited stock, so confirm on WhatsApp first) or five 10 kg bags (₹21,240.00). Both are ₹424.80 a kilo, so the choice is about handling, not price. For CSI 468 the order is 5 × 10 kg, ₹31,850.00.

Check the plan against your worst case. If a delivery takes 12 days at normal usage, you burn 20.00 kg while waiting and the order lands with 1.67 kg on the shelf — you have opened the safety bag, but you never stopped pouring. If that slow delivery also lands in a week running at 1.3× normal use, you would need 26.00 kg and would be 4.33 kg short — about 24 candles' worth. That is Method 2's warning: if your busiest weeks and your slowest deliveries really do coincide — a festive rush, for example — carry a second bag for those weeks only.

What the safety bag costs against what a stock-out costs

A 10 kg safety bag of Natural Soy Pearl is ₹4,248.00 of cash you do not use in a normal month. At an example holding rate of 1.5% a month that is ₹63.72 a month; in CSI 468 it is ₹95.55. Now price the alternative. Each day without wax is 9.1 candles not poured. If each candle contributes an example ₹150.00 after materials (your figure will differ — use your own), a single day's stock-out is about ₹1,358.70 of contribution delayed or lost, before counting late customer orders.

The arithmetic is lopsided in every realistic case: a year of holding a safety bag costs less than a single day without wax. That is why the question at 50 kg a month is never whether to hold safety stock, only how much. Overdoing it has its own cost — more cash on the shelf and more wax sitting through a hot summer — which is why the bag is rounded to one, not three. At 100 kg a month the next question becomes how often to order, and storing 100 kg through an Indian summer covers conditions.

The check every delivery gets, and the one the safety bag gets

At 50 kg a month you receive a delivery roughly every four weeks, and each one is, as far as you can prove, a new lot. CSI publishes no lot numbers or certificates of analysis, and nobody can promise you that two deliveries are identical. So two small checks keep the system honest. The first is the delivery check: three candles from the new delivery against three controls from retained approved stock. The second is the rotation rule: when a delivery arrives, the safety bag goes into production and a fresh bag becomes the new safety bag — so safety stock is never the oldest wax in the building.

Two waxes with a 10 kg bag and a 50 kg-a-month route

Both are priced here because both reach a 10 kg bag at their lowest listed per-kg rate, which is what a safety-stock system needs. CSI publishes no data showing one performs better than the other; if you are choosing between them, run them side by side in your jar first — the soy-wax qualification test sets the full protocol.

The decision rule

For the reader who asked: hold one 10 kg bag as safety stock and reorder 50 kg at 22 kg on hand. In Natural Soy Pearl the first order is 50 kg plus the safety bag, ₹25,488.00; in CSI 468, ₹38,220.00. After that, every order is one month — ₹21,240.00 or ₹31,850.00 — and every delivery gets the 3 + 3 check before it goes into production. What to verify when your first large-format pack arrives covers the inspection side, and the procurement system post puts pack size, trigger and safety stock into one table.

Frequently asked questions