Originally published January 22, 2025 | Updated August 12, 2026 | CheckSum
In this CheckSum customer application, a leading European automotive electronics manufacturer reduced untested work in process (WIP) by 99%, lowered production-test costs by 31%, and increased test output to 25% above the output of its surface-mount technology (SMT) line. The manufacturer achieved those results by replacing a sequential capacity constraint with parallel in-circuit test, device programming, and functional test for panelized printed circuit board assemblies (PCBAs).
The short answer: Higher-density panels multiplied the number of PCBAs produced during each SMT cycle, but the existing test process did not scale at the same rate. Parallel PCBA testing allowed multiple boards to be tested and programmed simultaneously, bringing test throughput back in line with production demand.
The manufacturer operated high-volume SMT lines for automotive electronics. Its smaller products were built in multi-up panels and represented a large, growing share of production. Despite the speed of the assembly operation, these products carried higher costs and greater quality risk than the company's larger assemblies.
The problem appeared after assembly. SMT output overwhelmed the PCBA production-test process, creating racks of untested panels. When a manufacturing defect was finally detected, thousands of PCBAs could already have passed through the line. That delay increased the exposure to sorting, rework, and scrap.
RECOMMENDED IN-ARTICLE IMAGE
Use an approved image of panelized PCBAs waiting for production test as the featured image or directly
after this section.
For this manufacturer, the SMT line could process an 8-up panel in about the same panel cycle as a 2-up panel. The output measured in individual PCBAs increased substantially, but testing the eight smaller boards took up to three times longer than
testing the two-board panel.
That difference occurred because assembly and test scale in different ways. SMT equipment processes one panel while placing the required components. Conventional test often repeats board-level operations for each device under test (DUT). As the panel changed from 4-up to 8-up and the factory installed faster pick-and-place equipment, the downstream mismatch became more severe.
Several factors contributed to the bottleneck.
Testing time depends on:
As panel sizes increased from four boards to eight or even twelve boards, test time increased much faster than SMT production time.
Meanwhile, newer, faster pick-and-place equipment accelerated production even further, causing WIP inventory to grow rapidly.
The factory had reached a point where test—not manufacturing—limited overall production capacity.
Like many global manufacturers, the company used corporate-approved equipment for:
Although these systems met corporate standards, they simply couldn't match the output of modern SMT production lines for highly panelized assemblies.
The factory needed a fundamentally different testing strategy—not just faster equipment.
Rather than testing one board at a time, CheckSum implemented a parallel testing strategy that allowed multiple boards to be tested simultaneously.
The solution combined:
By executing testing and programming operations across multiple PCBAs at the same time, overall throughput increased dramatically while maintaining test coverage and product quality.
Instead of allowing the test department to become the bottleneck, testing now kept pace with SMT production.
After implementing CheckSum's parallel testing technologies, the manufacturer achieved measurable improvements throughout the factory.
Perhaps most importantly, production teams received immediate feedback whenever manufacturing issues occurred, preventing thousands of defective boards from being produced before problems were identified.
As PCBAs become smaller and panel counts continue to increase, traditional one-board-at-a-time test strategies become increasingly difficult to justify.
Manufacturers that invest heavily in faster SMT equipment often overlook the downstream impact on test capacity.
Without matching improvements in testing, production bottlenecks simply shift from manufacturing to quality assurance.
Parallel testing restores balance across the manufacturing process by allowing test throughput to scale with SMT output.
If your factory is experiencing any of the following, your test process may be limiting overall manufacturing performance:
These are common indicators that your testing strategy—not your production line—is limiting throughput.
Modern SMT lines can produce panelized PCB assemblies faster than ever before. Unfortunately, traditional testing methods often cannot keep pace.
By implementing parallel In-Circuit Test, Parallel Programming, and Parallel Functional Test technologies, manufacturers can eliminate bottlenecks, reduce WIP, improve quality, and increase overall manufacturing efficiency.
For manufacturers producing high-volume automotive electronics, parallel testing isn't simply an upgrade—it's becoming a competitive necessity.
If your production lines are outpacing your test department, CheckSum can help.
Our automated test systems and parallel test technologies are designed specifically for high-volume manufacturers producing panelized PCB assemblies.
Contact CheckSum today to schedule a Parallel Test Project Analysis and discover how your factory can eliminate WIP, reduce manufacturing costs, and keep pace with today's fastest SMT production lines.