ABSTRACT
Control in Industry ......................................................................... 530 19.2 Technical Requirements Are Critical ......................................................... 531
19.2.1 Functional Tolerances Required for Zero-Defect Manufacturing ................................................................................ 532
19.2.1.1 Analytical Measurements with Coordinate Measuring Machines to Establish Functional Tolerances ................. 532
19.2.2 Process Control Uncertainty Contribution to Overall Process Uncertainty ..................................................................................... 533
19.3 Financial Analysis Involves Many Factors ................................................. 534 19.3.1 Comparison of Measurement Costs Per Workpiece ....................... 534
19.3.1.1 Fixed Costs ...................................................................... 536 19.3.1.2 Variable Costs .................................................................. 536
19.3.2 Determining Return on Investment for Direct ComputerControlled Coordinate Measuring Machines ................................. 537 19.3.2.1 Scrap and Rework Reduction ........................................... 538
19.3.3 A Sample Process Control Cost Comparison .................................540 19.3.4 Sample Gage and Fixture Calibration Cost Comparison ............... 542 19.3.5 Net Present Value Calculations ...................................................... 542
19.4 Summary ....................................................................................................544 Acknowledgments ................................................................................................. 545
Most projects involving capital investments are analyzed in terms of their projected pay-back to the business. The purchase of coordinate measuring machines* (CMMs) is no exception. Because a CMM is not a production tool, the pay-back analysis tends to be more sophisticated. This chapter points out that a CMM can have an even greater impact on the nancial success of a business than a production tool. Today, more than ever before, businesses must produce high-quality products at low cost to survive in the increasingly competitive global market. By keeping processes under control, scrap and rework are minimized, which reduces production costs, and if parts are consistent, then product quality will be superior.
