A quality information system framework for the mechanical component manufacturing industry is presented in this paper. Planning functions of quality control include process specification supported by a database, quality tool and control chart selection supported by a knowledge base, and quality control rig specification also supported by a knowledge base. Operation functions include data acquisition implemented on the basis of commercially available hardware and software, quality-related event capturing implemented in a database, quality data abstraction through statistical analysis implemented on a spread-sheet, and a shell for quality problems diagnostics and process improvement based on a comparison of quality-related events and process specification, both at generic and specific levels.