characteristics

In industrial and aerospace manufacturing, characteristics commonly refer to specific, measurable features, properties, or requirements of a part, material, or process that must be defined, produced, and verified. Characteristics are typically derived from engineering drawings, specifications, or customer requirements and are used as the basis for inspection and quality records.

What characteristics include in manufacturing

In regulated and aerospace environments, characteristics often include:

• Dimensional characteristics: lengths, diameters, hole locations, flatness, position, and other geometry called out on a drawing.
• Material and physical characteristics: alloy or resin type, hardness, tensile strength, grain direction, surface roughness, coating thickness.
• Functional characteristics: performance-related requirements such as pressure rating, flow rate, torque, electrical resistance, or continuity.
• Process characteristics: parameters that must be controlled in the process, such as heat-treat cycle, cure time and temperature, torque values, or test conditions.
• Key or critical characteristics: a subset of characteristics that have significant impact on safety, fit, function, or regulatory requirements and often require enhanced control and documentation.

Characteristics are usually identified and numbered during drawing review or ballooning, then referenced in inspection reports, first article inspection (FAI) forms, and electronic records in MES, QMS, or inspection systems.

Characteristics in AS9102 and First Article Inspection

In the context of AS9102 First Article Inspection, characteristics are the individual drawing or specification requirements that must be verified and documented for the part being qualified. Each characteristic is:

• Linked to a drawing or specification callout (often via a balloon number).
• Described in an inspection report (for example, AS9102 Form 3 fields).
• Associated with actual measured or observed results and the status of acceptance.

Consistent handling of characteristics is important for traceability, change control, and auditability across parts, suppliers, and revisions.

Operational role of characteristics

Operationally, characteristics are used to:

• Define what must be checked at receiving inspection, in-process inspection, and final inspection.
• Configure inspection plans, sampling plans, and electronic checklists in MES or quality systems.
• Support root cause analysis and nonconformance investigation by tying defects back to specific failed characteristics.
• Maintain evidence for internal and external audits by showing requirements, results, and dispositions.

Common confusion

Characteristics vs. tolerances: A characteristic is the feature or requirement itself (for example, hole diameter), while a tolerance is the acceptable variation for that characteristic (for example, 10.00 mm ± 0.05 mm).

Characteristics vs. requirements: “Requirements” is a broader term that can include process, documentation, and regulatory obligations. Characteristics usually refer to the specific, measurable technical or process features that are checked to confirm those requirements are met.

Tie-back to AS9102 audit risk context

In AS9102-related audits, gaps often involve how characteristics are identified, ballooned, transferred between PLM, MES, and QMS, and documented in FAI packages. Incomplete, inconsistent, or mismatched characteristic lists and results can create traceability issues and increase audit risk.