Characteristic ballooning is the practice of marking each inspectable requirement on an engineering drawing or model-based definition with a unique identifier, often shown as a numbered balloon or bubble. The identifier links the requirement to inspection records, measurement results, and quality documentation.
In manufacturing, characteristic ballooning is commonly used for first article inspection, in-process inspection planning, source inspection, and supplier quality review. A balloon may identify a dimension, tolerance, note, material requirement, finish callout, process requirement, or other verifiable characteristic.
The purpose is to create a clear cross-reference between the design requirement and the evidence that it was checked. For example, a numbered dimension on a drawing may correspond to the same characteristic number in an AS9102 Form 3 or an inspection report.
Characteristic ballooning should not be confused with measurement itself. Ballooning identifies and organizes the characteristics to be verified; it does not prove conformity unless it is linked to accepted inspection results and supporting records.