Cost Tracking
Accounting protocols in surface mount production assign direct financial charges for post-reflow touchup and component replacement to specific cost centers. Through line rework cost allocation, assembly facilities track manual soldering labor hours and damaged component costs against internal operator accounts or external client billing.
Defect Attribution
Attributing rework expense requires establishing the exact origin of each defect caught during automated optical inspection or functional testing. Solder bridging caused by incorrect stencil thickness charges the SMT setup account, whereas tombstoned components from defective component packaging land on vendor quality accounts. When line rework cost allocation identifies high rework hours on specific fine-pitch quad flat packages, engineering teams re-evaluate stencil apertures and reflow temperature profiles.
Clear tracking prevents high rework costs from inflating general overhead rates across unrelated production runs.
Variance Settlement
Commercial assembly contracts define thresholds where rework costs transition from standard shop floor operational overhead to billable customer expenses. Defective customer-furnished materials or unannounced board rev changes trigger chargebacks calculated from direct labor rates and specialized station depreciation fees. Establishing explicit line rework cost allocation procedures ensures transparent invoicing and historical data for pricing future build runs.
Standardized time-motion studies set maximum allowable rework time before a board assembly is scrapped entirely.
