Acceptance Quality Limit Sampling Plans for Lithium Cell Receiving Facilities
Enforce ANSI ASQ Z1.4 Level II sampling with AQL 0.010 for critical safety flaws and Kelvin OCV IR screening to reject defective lithium cells at receiving dock.
Reduced Inspection
Meaning
Quality control sampling regimes with lower frequency and smaller sample sizes are applied when a supplier consistently meets performance standards. Under reduced inspection, the testing workload is cut to lower costs and accelerate shipping times. This transition is governed by international standards, which define the conditions under which a factory can scale back its testing effort.
Sampling Frequency
Batch sampling is performed on a smaller portion of the incoming materials compared to standard plans. Transitioning to reduced inspection allows the quality team to focus resources on less reliable suppliers. This approach assumes that the risk of a major defect remains low.
Statistical Confidence
Fewer samples mean a slightly higher risk of accepting a defective batch, which is tolerated because of the supplier’s excellent track record. Before implementing reduced inspection, the manufacturer must verify that the process capability index has remained stable over a long period. This ensures that the risk remains within acceptable limits.
Quality Control
If a single batch fails the test, the plant must immediately return to standard or tightened inspection. Utilizing reduced inspection requires constant monitoring of the test data to capture any early signs of process drift. This ensures that the cost savings do not come at the expense of final product safety.
When the automated control charts show a rising trend in electrode deviations, the inspection rate is immediately increased to prevent any bad cells from entering the packing line.