General This Standard is primarily intended to apply to new parts, but can also be applied to parts currently in production. The Standard shall be applicable to all production processes that influence the variation of Key Characteristics. The variation control process begins with product definition, typically an engineering drawing or specification which identifies Key Characteristics and leads to a variation management program for those Key Characteristics. This process may also be used for Producer-identified Key Characteristics. Purpose This Standard is designed to drive the improvement of manufacturing processes through adequate planning and effective management of Key Characteristic variation. The Key Characteristic focus is intended to improve confidence for part features whose variation has a significant influence on end-product form, fit, performance, service life and manufacturability. Convention The following conventions are used in this standard: The words shall, will or must indicate mandatory requirements. The word should indicates a requirement with some flexibility allowed in compliance methodology. Producers choosing other methods to satisfy a should must be able to show that their approach meets the intent of the requirements of this standard. Words typical, example, for reference or e. g. indicate suggestions given for guidance only. Notes are used for additional clarifications. Words or phrases with specific meaning pertaining to this document are capitalized and defined in Clause 3, Terms and definitions.