How to Brief an OEM Craft/STEM Kit—and Build Your Own Costed BOM

Outcome

By the end, you’ll have:

1. a goal-driven parts list,

2. specs you can quote anywhere,

3. a costed BOM you can adjust line-by-line.

Step 1 — Lock the Learning Goal (what success looks like)

Fill this mini worksheet first:

• Age band & setting: e.g., 7–9, 45-minute classroom small-group (1–4 learners/kit)

• Core concept: circuits / magnetism / color theory / oral-motor + art / mechanics

• Outcome artifact: working model / poster / print / photo share

• Constraints: target EXW range, allergens, tools allowed/not allowed

• Assessment idea: one simple check (e.g., “LED lights with one switch,” “prints show two stenciling techniques”)

Keep this to one page—every part you add later must serve this goal.

Step 2 — Map Goal → Components (turn goals into parts)

Use this quick matrix to avoid over- or under-building:

Goal	Must-have components	Nice-to-have (swap for budget)
Basic circuits	Copper tape, LEDs, CR2032, switch tab, base card	Pre-cut templates, extra LEDs
Airbrush art (oral-motor + creativity)	Blow pens, stencil wheel/flat stencils, sketch pad	Chipboard masks, booklet, QR video
Magnetism	Bar magnets, iron filings viewer, activity card	Compass, magnet sorting cards

Rules of thumb

• 1 primary activity + 1 reinforcement = enough for 30–45 minutes.

• Add spares for classroom environments (3–5% typical).

Write each component as a row in your BOM with its function so you can delete anything that doesn’t serve the goal.

Step 3 — Pick Practical Specs (paper / wood / plastic / foam)

Choose from the ranges below to get quotes apples-to-apples across suppliers.

Paper/Card

• Inner pages: FSC 120–160 gsm offset/art

• Covers: 250–350 gsm C1S/C2S

• Inserts: Chipboard 1.5–2.0 mm

• Corrugated: E-flute or F-flute; CMYK, matte/OPP optionalCost levers: page count, print coverage, finish.

Wood

• Birch/Basswood ply 2–3 mm laser-cut; sand ≥240 grit; radius corners for K-6Cost levers: thickness, sheet yield, varnish.

Plastics

• Stencils: PP 0.5–1.0 mm; functional parts PS/ABS as neededCost levers: thickness, tool re-use.

Foams

• EVA 2–5 mm (Shore A 35–45) for grips/inserts; PE foam for protectionCost levers: thickness, die complexity.

Add your chosen spec into the BOM “Spec/Material” column so every quote uses the same language.

Step 4 — Build the Costed BOM (the spreadsheet that runs the show)

Create these columns (already set up in the template you can download):

• Component, Function, Spec/Material

• MOQ, Unit Cost (USD), Qty per kit ⇒ Ext Cost (Unit × Qty)

• Scrap/Spare % ⇒ Buffer Qty (e.g., 3–5% for paper/plastics)

• Alt Option A/B (spec + cost for trade-offs)

• Pack Location (inner/outer), HS code, Notes

Formulas to add

• Ext Cost = Unit Cost × Qty

• Buffer Qty = CEILING(Qty × (1 + Scrap%))

• BOM Subtotal = SUM of Ext Cost

Now layer on the non-BOM costs in the Cost Model sheet:

• Tooling/Artwork + Compliance (tests) → amortize:Amortized per unit = (Tooling + Compliance) / Planned Units

• Packaging & Assembly per unit (insert + labor)

• Freight per unit (total freight / units)

• Landed Unit Cost = BOM Subtotal + Amortized + Pack&Assembly + Freight

• (Optional) MSRP estimate: Landed / (1 − Margin)

Step 5 — Package & Pack-Out (test before you pay for print)

Pick one format and prototype plain first:

• Peggable window carton / gift box / eco mailer / classroom tub

• Print content to plan: age grade, warnings, barcode/lot, QR help, languages.

Run three fast checks with your pilot pack:

• Fit & protection: shake test; nothing rattles into damage.

• Openability: a child can open without tools; no loose magnets/sharp burrs.

• Drop test: 1.2 m on corners/edges/faces with no critical damage.

Record findings in your BOM “Notes,” then update specs.

Step 6 — Compliance & Labeling (budget it in)

• Plan for EN71 / ASTM F963 labeling; age grade, warnings, barcode, batch/lot.

• Add a line in your cost model for testing and amortize it.

• Keep a simple traceability note: supplier code + production month.

Step 7 — Freeze Changes & Make a Golden Sample

• Keep an ECO (engineering change order) log with dates and reasons.

• Lock artwork + fonts + color drawdowns on the dieline.

• Mark one Golden Sample and store it with the BOM PDF; this becomes the reference for any supplier.

RFQ Email Template (copy, paste, and attach your BOM)

Subject: RFQ – [Kit Name], [Qty], target EXW [$X–$Y]

Hello,Please quote the attached BOM with my specified materials and quantities.

• Packaging: [format], print CMYK, [finishes]

• Compliance & labels: [standards], [languages], barcode + batch code

• Sample timing: [date], Production timing: [date]

• Please list unit cost, MOQs, lead time, and any suggested cost-down alternates.Thank you.

Worked Example — Airbrush Art Kit (use as a pattern)

Essential tier (see downloadable CSV for full lines):

Component	Spec	Qty	Unit	Ext
Blow Pen	PP body, BPA/BPS-free	4	0.18	0.72
Stencil Wheel	PP 0.8 mm	1	0.12	0.12
Sketch Book	20p 140 gsm + 300 gsm cover	1	0.28	0.28
Chipboard Shapes	1.8 mm die-cut	8	0.09	0.72
Booklet	10p, full color	1	0.11	0.11
Mailer Carton	E-flute CMYK	1	0.42	0.42
Polybag/Labels	—	1	0.05	0.05
BOM Subtotal ≈ 2.42 USD before amortization, assembly, freight.

Use the Alt Option columns to tune up/down (e.g., “3 pens” vs “5 pens,” “16p book” vs “24p”). Update your Cost Model to see Landed Unit instantly.

Troubleshooting (quick fixes)

• Over budget? Cut page count, switch E-flute → kraft mailer, reduce stencil thickness 1.0 → 0.8 mm, or move booklet → QR card.

• Too heavy? Reduce chipboard thickness or page count; swap tub → mailer.

• Kids finish too fast? Add 1 reinforcement item (worksheet, extra mask shapes).

• Assembly jams? Add “Pack Location” column notes (inner vs outer) and reorder lines for a logical pack-out.