What are the AS9103 Rev. A Key Characteristics?

AS9100 Rev C mentions Key Characteristics several times.

9103A Definition:

The feature of a material or part whose variation has a significant influence on product fit, performance, service life or manufacturability

  • Key characteristic for a part, sub-assembly or system: selected geometrical, material properties, functional and cosmetic features which are measurable and whose variation is necessary in meeting Customer requirements
  • Key characteristic for a process: selected measurable parameters of a process whose control is essential
  • Substitute Key characteristic: when Customer defined key characteristic is not readily measurable and other characteristic may need to be controlled

Scope of 9103 Rev. A

  • Primarily intended to apply to new parts but should also be applied through out the life of the program to ensure that changes are taken into consideration
  • Establishes requirements for management of key characteristics variation
  • Specifies general requirements
  • Provides a process

Managing Variation in Key Characteristics (AAQG)


IAQG has an excellent Key Characteristics Presentation, listed here for your convenience:

The presentation outlines the seven stages process for Key Characteristics

AS9103 Key Characteristics

  1. Understand KCs and required performance
  2. Plan Manufacturing Processes
  3. Operate on Trial Basis to generate Data
  4. Analyse data to identify appropriate Action
  5. Take action from study
  6. Continue to Monitor the Performance
  7. Is a process change required?

More Info:

  • AAQG Key Characteristic Variation Presentation
  • SAE AS9017 Control of Aviation Critical Safety Items (CSI) may apply
    • AS9017-requirements for CSI management for organizations and suppliers who perform work for prime contractors receiving direct contracts from U.S. government agencies. (1st Tier or Prime suppliers)
    • AS9107 is auditable with the expectation that the prime contractor will flow CSI requirements to the supply chain and periodically assess, audit, validate, and recognize compliance to AS9017 per their own processes.


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