I Consume 25 Kg of Wax Every Week — How Much Stock Should I Maintain if Supplier Deliveries Are Normally Reliable?

What "normally reliable" is actually worth

A reliable supply line is worth real money and it should change your policy. The mistake is to treat it as a reason to hold nothing, because reliability and variability are not opposites. A supplier who delivers in six to eight days, every time, for a year, is extremely reliable — and still has a two-day spread. Your buffer is not insurance against your supplier being bad. It is insurance against the gap between the typical delivery and the slowest one you have actually seen.

Split the buffer explicitly, because the two halves behave differently and reliability only touches one of them.

Read the last row carefully, because it is the honest version of the answer to the title question. Proven reliability is worth about 8 kg of wax to you — the difference between a 43 kg reorder point and a 35 kg one. At CSI 464 pricing that is ₹4,059.20 of working capital you get back for having a supplier whose deliveries do not vary. It is a genuine saving and it is not a licence to run on fumes.

One point of honesty that this whole page rests on. Every lead-time figure here is yours, not ours. CSI publishes no delivery times, this guide states none, and the seven-day and ten-day numbers above are illustrations of the method. Go and get your own: open your order history, write down the gap between payment and wax-on-bench for the last six to ten orders, and use the longest. That single number does more for your inventory policy than any formula.

The reorder point at five lead times

The formula is reorder point = average daily consumption × lead-time days + safety stock, and at 25 kg a week the daily rate is fixed at 3.57 kg. So the only input that moves is your lead time — which is why the single most valuable half-hour you can spend on inventory is measuring it. The table holds the demand buffer at 7 kg and sets the lead-time buffer at three days of consumption in each case, so you can see what the lead time alone does.

Notice what the table does not say. It does not give you a holding level, because a reorder point and a holding level answer different questions. The reorder point stops stock-outs. The holding level is simply the reorder point plus whatever you buy in one go, and it is a cash decision rather than a safety one. Order 25 kg weekly and you peak at 68 kg; order 50 kg fortnightly and you peak at 93 kg; order 100 kg monthly and you peak at 143 kg — with identical protection in all three cases, because the protection lives in the trigger.

That is the real argument for a weekly cadence when your supply is reliable. Ordering 25 kg every week rather than 100 kg every month takes your average holding from about 93 kg to about 55 kg, which at CSI 464 pricing is roughly ₹19,000 of cash released with no change in stock-out risk. The cost is four orders a month instead of one, and — because the per-kilo price does not fall with pack size on most CSI waxes — almost no price penalty for buying in smaller parcels.

Buying 25 kg when 25 kg is not a listed pack

CSI does not list a 25 kg soy wax pack. The largest listed packs are 10 kg on most waxes, 5 kg on Eco Soy CSI 400 and 50 kg on Natural Soy Pearl Wax. So a 25 kg week is always a combination, and because several waxes are priced flat per kilogram across packs — and one is priced slightly against the big bag — the combination you choose occasionally matters.

Two of those rows are worth remembering. On Luxury Soy Wax Chunks, twenty-five single kilos list at ₹14,975 while two 10 kg bags plus a 5 kg bag list at ₹14,993 — the larger packs are ₹18 dearer, because the 10 kg bag works out at ₹599.90/kg against ₹599/kg at a single kilo. Nobody should restructure a weekly order over ₹18, but everybody should stop repeating the assumption that bigger is automatically cheaper. On CSI 468, the opposite is true and the amount is real: the 5 kg and 10 kg packs are ₹637/kg against ₹650/kg at a kilo, so buying in big bags saves ₹325 a week, or about ₹16,900 a year.

And the practical side of a weekly cadence: five 5 kg bags is five things to receive, check and store every week, against three on a 10 kg-led order. At 25 kg a week you are handling 1,300 kg a year, and the difference between 260 bags and 156 bags of handling is not nothing. If your storage is cramped, the 10 kg-led combination is usually the easier week even where it costs a few rupees more.

Which wax suits a weekly cadence

At a weekly order the wax you want is one whose per-kilo rate does not punish you for buying 25 kg at a time, and whose product page gives you numbers to hold your process to. Each card shows every listed pack, the per-kilo rate and candles per pack at a 185 g fill, plus what the weekly basket costs.

What one missed delivery costs

Safety stock is bought with cash and sold against lost production, so the only way to size it honestly is to know what a lost pour day is worth. At 25 kg a week over five pour days you consume 5 kg a pour day, which at a 185 g fill is about 27 candles. A full lost week is 135 candles.

The fourth column is the one spreadsheets miss. A candle is not finished when it is poured — soy container candles are normally cured 14 to 21 days before they are fit to sell, and that time cannot be compressed by working harder next week. So a three-day stock-out does not cost you three days; it moves your entire sellable stock three days to the right, including everything already promised. That asymmetry is the whole case for holding a buffer whose cash cost you can see and whose benefit you cannot.

Set against that, the cost of holding is easy to compute and easy to over-fear. The 18 kg buffer at CSI 464 pricing is ₹9,133.20 of wax that sits there permanently. Against 1,300 kg a year — ₹6,59,620 of wax at CSI 464, or ₹5,18,960 on Eco Soy CSI 400 — that buffer is under 1.4% of annual wax spend. Very few insurance policies are that cheap, and almost none of them are refundable: unlike most insurance, your buffer is still wax, and you will eventually pour it.

Running the weekly cycle

Five steps, once a week, about ten minutes. The point of writing it down is that a weekly cadence only works if the check happens on a fixed day — drift the check and you drift the reorder point with it.

Proving your supplier is reliable

"Normally reliable" is a belief until it is a column of dates. Here is the smallest possible record that turns it into a number you can put in a formula, and what each column is for.

Use the median of the Days column for your pipeline and the maximum for your lead-time buffer. If ten orders came in between six and eight days, your median is seven and your spread is two — so the lead-time buffer is 2 × 3.57 = 7.14 kg rather than the 10.71 kg used in the tables above, and your reorder point drops from 43 kg to about 39 kg. That is ₹2,029.60 of CSI 464 released on the strength of your own records, which is the most honest kind of inventory saving there is.

Keep one eye on the fourth column. A supplier who is reliable on dates but occasionally short on quantity produces exactly the same stock-out as a late delivery, and no amount of lead-time precision protects you from it. If "short by" is ever non-zero, the buffer has to absorb that too — and the check that catches it is weighing the delivery, not glancing at the box count.

Finally, revisit the whole calculation on a cadence rather than when something goes wrong. Twenty-five kilos a week becomes thirty-two kilos a week faster than you expect, and a reorder point expressed in kilograms silently loses days of cover as your daily rate climbs: 43 kg is 1.7 weeks at 25 kg a week but only 1.3 weeks at 32 kg. Quarterly is a sensible review; immediately is the right answer if your weekly consumption has moved by more than a fifth. The growth version of this problem is laid out in converting monthly candle sales into kilograms of wax.

Frequently asked questions