This paper describes a proof-of-concept computer system capable of interpreting graphical component connectivity in Process and Instrumentation Drawings (P&IDs). The input drawing is a CAD file in DXF format (AutoCAD Release 12, Advanced Tools Manual, Autodesk Inc., 1993, Chapter 6). Drawing features are considered to be pipes or symbolic entities with geometrically constrained attachment ports. A low-level image processing front-end is currently being developed to support the interpretation of drawings in vector format from scanned paper P&IDs. A hierarchical data structure is used to enable recognition of components in collinear and circuit complexes.
