Meaning
Statistical sampling methods determine the maximum number of defective units allowed in a batch for it to be accepted during quality control audits. In battery cell procurement, incoming inspection aql establishes the sampling plan and acceptance thresholds for incoming shipments of cells or raw materials. This metric protects the buyer from receiving large quantities of sub-standard components while keeping inspection costs manageable.
Sampling Plan
The plan defines how many cells must be randomly selected and tested from each incoming lot based on the total lot size. If the number of failed cells in the sample exceeds the acceptance threshold, the entire lot is rejected and returned to the supplier. This structured approach ensures that inspection resources are focused on the most critical safety and performance metrics.
Procurement Leverage
Having a defined quality threshold in the supply contract gives the buyer a clear legal mechanism for rejecting bad shipments. This helps to enforce high standards of manufacturing quality at the supplier’s factory. It also reduces the need for expensive, hundred percent inspection of every incoming cell.
Risk Management
Sourcing teams must set the threshold based on the criticality of the component. For example, safety-critical components like current interrupt devices require a much lower defect threshold. Balancing these thresholds protects the final product quality.
