The trade-off in one sentence
Order in small batches and you pay more per piece, more often, in freight and handling. Order in large batches and you pay less per piece but tie up cash in stock that may sit for months. Batch sizing is the search for the point where the saving on price stops being worth the cost of holding.
The economic order quantity idea is simply that search written down. It says the right batch balances two costs that move in opposite directions: the cost of placing and shipping an order, which falls as batches grow, and the cost of holding the stock, which rises as batches grow. Where the two cross is the size that costs least in total, not the size with the lowest unit price.
Carrying cost is real money, even when nothing moves
Carrying cost is the part buyers most often leave out. It includes the interest on the cash tied up, the space the stock occupies, insurance, and the risk that the stock is damaged, superseded or simply never sold. A rough figure for all of it together, applied to the average value of the stock held, is enough to make the comparison honest.
Slow-moving lines make this plainest. A batch of consumables turns over in weeks, so the carrying cost is small and a larger batch is easy to justify. The same logic applied to a slow assembly ties up a large sum for a long time, and the unit-price saving rarely covers it. The right batch size is per item family, not one number for the whole order.
Freight and exchange move the answer
Two external inputs change the calculation month to month. The first is freight. When container rates are high, consolidating into fewer, fuller shipments saves real money, which argues for larger batches of the lines that justify them. When rates are low, the freight penalty on small batches shrinks and the case for holding stock weakens.
The second is exchange rate. A buyer paying in one currency against a supplier billing in another is exposed to the move between the order date and the payment date. If the rate is favorable now and the payment terms are short, a slightly larger batch can lock in that rate on more goods. If the rate is moving against the buyer, a smaller batch and a shorter commitment limit the exposure. Neither input belongs in a unit price alone; both belong in the decision.
Sizing a batch with the numbers you actually have
Precise models need data most buyers do not have. A workable substitute is to sort lines into three bands by how fast they turn, and set the batch rule per band. Fast movers are ordered to cover a short period with a modest buffer. Medium movers are ordered to cover a longer period, because the order cost is spread over more value. Slow movers are ordered only against a known need, because the carrying cost swamps any price break.
Then check the batch against one more thing: the cash it removes from the bank on the day it is paid for. A batch that is efficient on paper but empties the working capital is not a good batch. Guangzhou Shenyue Machinery Technology Co., Ltd. quotes heavy and light lines together so that a container's freight can be shared across a mixed load, which lets a buyer raise the batch on the cheap consumables without raising it on the expensive assemblies.
Where we fit
Guangzhou Shenyue Machinery Technology Co., Ltd. has supplied excavator parts from Guangzhou since 2007. Four warehouses hold 3,000+ part types on the shelf, with 100,000+ part numbers available to order through original supply channels — which is the same structure a buyer builds for itself, fast movers held locally and slow movers sourced against a need.
We are an independent supplier, formally authorized for five brands — Garrett, Mitsubishi Heavy Industries, TONGMYUNG, NIKURA and Marusan — and supplying other machine brands through original supply channels or as OEM-quality and aftermarket lines, with the grade stated on every line of a quotation. That written grade is what lets a buyer decide which lines are worth a large batch and which are worth a small one.
Frequently asked
Is the lowest unit price always the best batch?
No, and it is often the most expensive one. A low unit price bought in a batch larger than the demand justifies simply moves money from the bank into a shelf, and the interest, space and obsolescence on that stock can cost more than the price saving. The right comparison is total cost over the period the stock lasts, not the price on the invoice. Guangzhou Shenyue Machinery Technology Co., Ltd. will quote a smaller batch when a larger one would sit.
How do freight rates change the answer?
When rates are high, fuller and fewer shipments win, which favors larger batches of the lines that deserve them. When rates are low, the penalty on small and frequent orders falls, so the case for holding extra stock weakens. Either way, the freight belongs in the decision alongside the price, not as a separate line reviewed later.
Should a first order from a new supplier be large?
No. A new supplier should be tested with a batch small enough to lose and large enough to judge handling, packing and documents. Batch sizing assumes a supplier whose lead time and quality are known; until they are, the risk belongs in the batch size rather than in the faith placed in the supplier.
Send the machine model, serial number, the part numbers you have and the quantity. That is all we need to quote and confirm fitment before payment.
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