Reduction of production defects by 12.4% in an electronics factory
We introduced a visual control system on 3 assembly lines in Słupsk. The number of rejects fell from 17 to 4 units for every batch of 1,000.
An electronics factory near Słupsk struggled with a high percentage of defective PCBs. Our task was simple: find the cause of the errors on the assembly line and remove it without stopping shipments to contractors.
The challenge
In June 2024, line 3 generated an average of 17 rejects for every 1,000 finished units. Each defective piece is a loss of 42.30 PLN in raw materials and labor. Monthly, the plant threw away goods worth 7,340 PLN because errors were detected only at the very end of the process, during functional testing.
Operators worked in poor light, which meant they missed solder micro-cracks in 8 out of 10 cases. There was also a lack of a clear procedure on what to do when a series of three erroneous items appeared on the line in a row. The line continued to work, duplicating the error and generating further costs.
Our approach
Marek Wiśniewski together with two consultants spent 9 business days directly on the floor in Słupsk. We did not analyze tables in the office – we did snapshot observation at the soldering stations. We checked the angle of lamps and the ergonomics of 14 operators' work.
We calculated that eye fatigue after 4 hours of a shift drastically increases the number of missed defects. We focused on facts: we analyzed 1,247 recent reports from the quality control department to pinpoint specific spots on the board that cause the most problems.
The solution
We introduced a visual control system based on physical patterns at each station. We changed the lighting to LED points with a temperature of 5600K, which improved detail visibility by 37.4%. This allowed workers to catch imperfections faster without straining their eyes.
We also implemented a simple Poka-Yoke mechanism: each operator received a marker for designating a specific error zone, which shortened repair time by 4 minutes per piece. Additionally, we launched an Andon system – now every anomaly stops the line in 4 seconds, which prevents production of entire series of defects.
Results
Three months after implementation, the number of defects dropped by more than 12 percentage points. The factory is recovering money that was previously wasted in scrap, and the team works more calmly.
Timeline
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12-14 June 2024Light intensity measurements and analysis of 1,247 errors from production history.
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July 2024Installation of new lighting and implementation of Andon boards on 3 lines.
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18-22 August 2024Training for 14 operators and final verification of financial results.
"Baltic Bridge Consulting did not waste our time on presentations. They entered the floor, found the lighting problem and fixed it. Numbers don't lie – we save almost 5 thousand a month."