Cost Estimation

What Drives Cost Per Unit in Diagnostic Kit Manufacturing

A bottom up cost model for diagnostic kits, from landed materials and cleanroom occupancy to return investigations and the overhead generalists underprice.

Cost per diagnostic kit breaks into five buckets: bill of materials, direct assembly and packaging labor, machine and cleanroom time, scrap and rework, and loaded overhead. For a mid volume immunoassay kit, materials typically run 45 to 60 percent of factory cost, labor 15 to 25 percent, cleanroom and equipment time 8 to 15 percent, and quality overhead the balance. The mistake estimators make is quoting off a clean bill of materials and bolting a flat percentage onto everything else. In this category the quality and documentation load is heavy enough that a flat markup buries real money, especially on short runs where fixed costs per unit climb fast.

Start the bill of materials at landed cost, not list price. A five component kit might carry a 0.65 dollar cartridge, 0.28 dollar buffer vial, 0.40 dollar lyophilized reagent, 0.12 dollar desiccant pouch, and 0.35 dollar printed insert, so 1.80 dollars in raw parts. Add inbound freight and duty at 4 to 8 percent, then a scrap allowance from your Reagent Fill Yield number. If fill yield is 94.8 percent, you buy bulk for 100 kits to ship 94.8, so effective reagent cost divides by 0.948, lifting the 0.40 dollar reagent to 0.42 dollars. Materials land near 1.95 dollars before a single operator touches the line.

Convert assembly labor minutes into dollars with a fully loaded rate, usually 28 to 45 dollars per operator hour in a regulated cleanroom once benefits, gowning time, and supervision are included. At 4.33 minutes of assembly labor per kit and 38 dollars per hour, direct assembly is 2.74 dollars. Cleanroom packaging adds its own time; the Cleanroom Packaging Labor calculator might show 1.8 minutes per kit for pouch loading and seal verification, another 1.14 dollars. Gowning and line clearance are real but easy to omit, often 20 to 30 minutes per operator per shift that must spread across shift volume, not vanish from the estimate.

Cleanroom and equipment time is an occupancy cost, charged per hour the kit occupies classified space. An ISO 7 suite can cost 150 to 400 dollars per hour once HVAC, gowning consumables, and environmental monitoring are loaded. If a line makes 65 kits per hour, occupancy adds 2.30 to 6.15 dollars per kit, a range wide enough to swing the whole quote. Sterile Pouch Throughput drives this directly: raising effective sealer output from 675 to 810 pouches per hour by lifting OEE from 0.75 to 0.90 cuts per kit occupancy by roughly 17 percent without touching labor rates or material spend.

Scrap and returns are where soft quotes go wrong. A 5 percent field return rate on a kit that cost 8.00 dollars to make is not a 0.40 dollar problem; each returned kit triggers an investigation. The Returned Kit Investigation Cost calculator commonly lands at 180 to 450 dollars per event once QA labor, root cause, and CAPA documentation are counted, so 5 returns per 10,000 kits adds 0.09 to 0.23 dollars per unit shipped. Internal scrap from fill loss, seal failures at 1 to 3 percent, and labeling rejects each carry the full sunk material and labor, not just the raw part price.

Regulatory overhead is the bucket generalist estimators underprice. Lot release testing from your Lot Release Sample Load figure, at 40 QC hours per 10,000 unit lot and 55 dollars per hour, is 0.22 dollars per kit. Labeling Compliance Burden adds review, translation, and UDI reconciliation that can run 15 to 30 minutes per SKU per lot. Batch Genealogy Workload for device history record review adds 2.4 to 4.0 hours per lot. Together, quality and documentation frequently reach 12 to 18 percent of factory cost on low volume kits, which is why quoting a flat 10 percent overhead loses money on every short run.

Build the quote bottom up and stress it. Sum materials at 1.95 dollars, assembly and packaging labor at 3.88 dollars, cleanroom occupancy at 3.50 dollars, scrap and returns at 0.35 dollars, and quality overhead at 1.10 dollars, for a factory cost near 10.78 dollars, then add target margin last. Test volume sensitivity: at half the annual volume, fixed lot release and genealogy costs per kit roughly double, pushing factory cost past 12 dollars. Quote a price break at the volume where occupancy and QC per unit stabilize, and use Kit Component Shortage Risk to price expedite and buffer stock into longer commitments rather than absorbing it.

Published 2026-07-02.