A hands-on engineer shadowed two EMS factories running full ASM and Panasonic lines. Results: 11-minute changeovers with ASM feeder carts, sub-8 µm stability on Panasonic medical panels. Spare-parts strategy, service response, and operator quotes included—no brochures, just measured data.

I've debugged enough placement machines to know marketing slides lie. So I grabbed a stopwatch and measured two lines in the wild.

Factory 1 - Full ASM SMT Line

Printer: DEK Horizon
Placers: Siplace TX2 + TX1
Reflow: Rehm VisionXP+

Daily reality: 4 automotive BOMs, 3,500 boards/shift. Old changeover averaged 42 minutes—feeders scattered, nozzle trays misplaced, recipe load stalling the MES.
ASM's counterpunch: rolling feeder islands. Tech pre-kits tomorrow's reels offline; wheels the cart to the machine; feeders auto-ID via RFID. Total stoppage: 11 minutes 08 seconds gate-to-gate.
Placement check on 0201s: 99.97 % first-pass yield, DPMO 280. One operator botched a nozzle install—cross-threaded the retainer. ASM's local FE arrived in 43 minutes, retrained the whole shift in 12 minutes. Problem solved permanently.
Factory 2 - Panasonic NPM Ecosystem

Printer: SPG
Placers: NPM-D3 + NPM-W2
Reflow: integrated

Product: Class III medical wearables, 60 changeovers/week, 280 components/panel. Drift on 0.15 mm QFNs after reflow was killing yield.
Panasonic's answer: Autotronik vision recalibrates every 50 panels. I logged X/Y offset under 8 µm across a 6-hour thermal cycle. Head swap is four thumbscrews and a QR code—4 minutes, no jig.
Software caveat: new nozzle approval needs factory mode; 15-minute reboot. Still, unplanned downtime hovered at 1.2 %.
Inventory Math
ASM: one feeder baseplate fits printer + both TX placers → 68 % fewer SKUs.
Panasonic: 14 unique head modules; elegant but pricey.
Service SLA
ASM: local FE on-site 43 min after midnight call.
Panasonic: tier-1 parts same-day, tier-2 escalates to California—14 h median.
Bottom Line
If your scheduler looks like a ransom note, ASM SMT line flexibility is oxygen. If every placement is FDA-audited, Panasonic's locked-down stability is the safer bet. Match the line to the chaos level of your forecast.