Product and manufacturing information
Product and manufacturing information, also abbreviated PMI, conveys non-geometric attributes in 3D computer-aided design (CAD) and Collaborative Product Development systems necessary for manufacturing product components or subsystems. PMI may include geometric dimensions and tolerances, 3D annotation (text) and dimensions, surface finish, and material specifications. CAD application literature may also refer to PMI synonymously with Geometric Dimensions and Tolerances (GD&T) or Functional Tolerancing and Annotation (FT&A).
Industry standards for defining PMI include ASME Y14.41-2003 Digital Product Data Definition Practices and ISO 1101:2004 Geometrical Product Specifications (GPS) -- Geometrical tolerancing—Tolerances of form, orientation, location and run-out. In an effort to unify the visualization of PMI across the different existing solutions, Adobe Systems has released a version of the Myriad CAD font that allows display of PMI information from almost any CAD application. Similarly, Siemens PLM Software offers downloadable font sets for multiple languages such as for Asian character sets. The ISO 10303 STEP standards also handle a wide range of PMI information.
The PMI annotation is created on the 3D CAD model, associated to edges and faces, and can be exported into neutral formats such as Siemens JT and ISO 10303 STEP. This information can then be used by a number of down-stream processes. Although PMI can be used to generate annotation on a traditional 2D drawing the data can be visualized within the 3D model by other departments, either in the CAD/CAM system or in a 3D Product visualization tool, thus reducing the need for drawings (Drawing on Demand). Some 3D model formats enable computer-aided manufacturing software to access PMI directly for CNC programming. The PMI also may be used by tolerance analysis and Coordinate-measuring machine (CMM) software applications if the modeling application permits.
PMI items are often organized under PMI Views. A PMI View is a view including camera/view position and also the particular state of the assembly (visibility, rendering mode, sometime even position of each element of the assembly). CAD applications have different notions of PMI Views (for instance "Capture Views" and "Annotation Views" are specific to Dassault Systems CATIA, etc.).
- "PMI / FT&A / GD&T DEMO" (PDF). Nihon Unisys. Retrieved 2009-06-17.
- "ISO Products, Standards". ISO TC 213 Dimensional and geometrical product specifications and verification. Retrieved 2009-06-17.
- NIST MBE PMI Validation and Conformance Testing Project (free CAD models with PMI)
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