1.1 Purpose This standard establishes requirements when implementing statistical product acceptance methods to meet defined risk requirements. This standard also establishes the minimum content required to be covered in an organization s documented procedures that govern their application of statistical product acceptance methods. These general requirements and documented procedures apply the requirements of the EN 9100/ EN 9110/EN 9120 quality management system standards, in addition to establishing requirements for retrievability, safety/critical characteristics, and quality parameters that protect the customer. 1.2 Application This standard is applicable when invoked in a purchasing contract or specification, contractual document, customer agreement, or adopted by the organization. The purchase contract/agreement may or may not identify the appropriate EN 9138 clause(s) to be applied by the organization. All statistical methods of product acceptance require the use of clauses 4 and 5. To accept product produced: by individual lots, see clause 6; under switching rules, see clause 7; under process controls, see clause 8; and by continuous sampling or special case methods, see clause 9.