AQL and RQL

Investors and operators pay  special attention to quality of the solar panels constituting the photovoltaic system. The statistical theory of quality control tells us that one has to use Acceptance Sampling Plans.

Having defined when a module is non-conforming, one considers the fraction of non-conforming modules in the shipment. The quality of the shipment is defined in terms of that fraction.

The Acceptable Quality Level (AQL) is the largest fraction of non-conforming modules that is still regarded as high quality.

The Rejectable Quality Level (RQL) is the smallest fraction of non-conforming modules that is still regarded as low quality.

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                         AQL                       RQL