At 800 sheets a month, how far apart are an own store and consignment?

Answer: 8,720 against 10,272 yuan a month, a gap of 1,552, or 18,600 a year at 6% scrap. At 3% scrap the gap narrows to about 9,300.

Outsourcing is 6 yuan a sheet, so why keep a store at all?

Answer: Lead time. A bureau needs 8 days, an own store needs none, and one 2,400 yuan stoppage eats the year's processing saving.

How do you hold stock down when part numbers multiply?

Answer: Split 80/20: top 20 as sheet, the other 60 outsourced. Every 10 extra part numbers needs 6 m² more floor, adding 1.4 yuan a sheet.

Can a vendor hold the consignment premium over you?

Answer: Yes, without a clause. Fix a step price: above 1,000 sheets the premium falls from 12 yuan to 8, with 90 days' notice.

Build, Consign or Outsource: Foam Inventory Management Costs

Quick answer: Which Foam Inventory Management model pays depends on monthly volume, part count and rush orders. At 800 sheets a month an own store costs 8,720 yuan, consignment 10,272, outsourcing 6.2 yuan a sheet — an 18,000 yuan gap a year.

Three costs before any mode: cash, scrap, downtime
Roll, sheet or moulded insert
Own store versus consignment
Outsourced cutting: stock traded for eight days
Four thresholds
FAQ

1. Three costs before any mode: cash, scrap, downtime

An instrument-case plant uses 800 sheets of 30 mm EVA a month at 42 yuan each: 33,600 yuan in material. At that volume Foam Inventory Management is three costs stacked on one decision.

Cash first: stock at 18% annual cost ties up 504 yuan a month, standing racks take 60 m² at 45 yuan, or 2,700, scrap at 6% adds 2,016, and half a storekeeper costs 3,500. Total 8,720 yuan.

Cost line	Basis	Own store	Vendor consignment
Cash tied up	Stock × 18% a year	504 yuan/month	0
Floor space	60 m² × 45 yuan	2,700 yuan/month	0
Labour	0.5 person × 3,500	3,500 yuan/month	0
Scrap	Stock value × 6%	2,016 yuan/month	672 yuan/month
Total	—	8,720 yuan/month	plus 9,600 premium

Divide 8,720 by 800 and an own store lands at 10.9 yuan a sheet. Consignment drops floor and labour but charges 12 yuan, with scrap at 2%, so it lands at 12.8. The gap is not unit price but diluted fixed cost.

Downtime is the third: 2 hours of stopped line at 1,200 yuan an hour costs 2,400 yuan, usually because the wrong density was bought.

2. Roll, sheet or moulded insert

Roll is the cheapest material and the dearest labour: 1.5 m wide, 25 kg, 18 yuan a kilogram, 9% offcut once you cut and label it.

Foam Inventory Management: a closed dark grey plastic case on a worn wooden bench, workshop shelves, timber and a bandsaw behind

Sheet is the middle path: 500 × 400 mm, 42 yuan a sheet, 4% offcut, 50-sheet minimum, which suits Foam Inventory Management across many part numbers in short batches.

Moulded inserts cost most to start and least to run: a 35,000 yuan tool, 200-set minimum, 76 yuan a set, 1% offcut. Below 500 sets a year the tool adds 70 yuan a unit, and a hand-cut sheet wins.

Changeover belongs in the same sum: 25 minutes of knife setting for a roll, 5 for a sheet, 40 for a mould plus a trial. Past 30 changeovers a month, the roll saving disappears into labour.

3. Own store versus consignment

The crossover sits near 680 sheets a month. Below it, fixed cost cannot be diluted: 8,720 yuan over 500 sheets is 17.4 each, while consignment at 12.8 is 4.6 cheaper.

Consignment charges 12 yuan a sheet and restocks in 3 days. The vendor audits quarterly, bills on withdrawal and offers 60-day terms, which is why consignment suits Foam Inventory Management.

Three signals argue against an own store: over 40 part numbers, under 25 m² of floor, volume below 680 sheets. Two of the three and consignment fits better. Above 900 sheets on a stable 20-part range, 10.9 yuan a sheet justifies the racks.

Metric	Own store	Consignment	Outsourced cutting
Fixed cost	8,720 yuan	0	0
Unit cost, 800 sheets	10.9 yuan	12.8 yuan	6.2 yuan
Replenishment	Stock	3 days	8 days
Minimum order	—	100 sheets	50 sheets
Part numbers	Up to 40	40–80	Above 80

The premium is negotiated annually and will not fall with volume. Write a step clause: above 1,000 sheets, 12 yuan becomes 8. Put count variance in the contract; above 2% the vendor absorbs it, while an own store swallows 3% shrinkage, about 1,000 yuan a year.

4. Outsourced cutting: stock traded for eight days

Cutting bureaus charge 6 yuan a sheet, take 50-sheet orders, deliver in 8 days. At 800 sheets that is 4,800 yuan, or 3,920 below an own store.

Foam Inventory Management: an open black hard case on a bench, convoluted foam in the lid, empty square foam cells below, tool drawers behind

The saving goes into buffer stock: 8 days of cover needs 150 sheets, about 6,300 yuan, or 189 yuan a month to carry. Foam Inventory Management through a bureau also moves the warehouse off site.

What a bureau cannot absorb is urgency: above 15% of orders inside 48 hours, you need 150 more sheets or a cutting table of your own. A stoppage costs 2,400 yuan, more than the fee saved.

Three cases argue against outsourcing: drawings that still change within 3 months, parts over 1.2 m, clients who want a liner swapped the same day. Keep the knife in-house.

5. Four thresholds

Recalculate these four numbers yearly rather than arguing preference.

Threshold	Below it	Above it	Why
680 sheets a month	Consignment	Own store or outsource	Fixed cost dilution
40 part numbers	Own store	Outsource	Rack space and knife changes
15% rush orders	Outsource	Hold 150 sheets	A stoppage costs 2,400 yuan
25 m² of floor	Consignment or outsource	Own store	Standing rolls need width

Thresholds collide: at 500 sheets, 60 part numbers and 20% rush orders no model fits alone. Stock 20 fast movers, outsource the rest, cover rush orders by consignment. Mature Foam Inventory Management is a switching cost, not a warehouse.

Conclusion

An own store buys lead time, consignment buys cash, outsourcing buys unit price. Foam Inventory Management has no best answer, only the model matching volume, part count and rush orders, rechecked yearly.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.