Eston Martz And Carly Barry 2015-02-24 00:16:54
It’s a common scenario faced by many manufacturers: your customer comes to you with production requirements that must be met. But how can you be sure that your products will meet those requirements? Suppose you are a parts manufacturer recently hired by a major auto company to produce new steel parts that meet a minimum tensile strength requirement of at least 600 megapascals (MPa). Using Monte Carlo simulation and optimization techniques with software such as Devize—a powerful new tool from Minitab—you can ensure that the steel parts will meet your customer’s specifications. BUILDING YOUR PROCESS MODEL Monte Carlo simulation uses repeated random sampling to simulate data for a given mathematical model and evaluates the outcome. Simulated data is routinely used in situations where gathering real data would be too expensive, time-consuming, or impractical. This example shows how Monte Carlo simulation can be implemented in a manufacturing environment to assess and optimize product results. The important inputs for this process are the melting temperature of the steel and the amount of carbon, manganese, cobalt, and phosphorus it contains. The following transfer equation describes the relationship between the key inputs and the steel’s tensile strength: Strength = -1434 + 1.1101*MeltTemp + 1495*Carbon + 174.3*Manganese - 7585*Cobalt - 3023*Phosphorus Using the transfer equation, in addition to the distribution information for each process input, you can assess the process capability and determine how well your process outputs meet specifications. UNDERSTANDING YOUR RESULTS In seconds, Devize shows you the predicted capability for your product results: The process performance measurement (Ppk) for your process is 0.34, far short of the minimum standard of 1.33. Devize also indicates that under current conditions, more than 15 percent of your parts won’t meet the minimum specification. OPTIMIZING YOUR INPUTS Following the poor results revealed by the Monte Carlo simulation, Devize then provides recommended next steps, such as Parameter Optimization, to help you improve your process. For the Parameter Optimization, you select the goal—maximizing the Ppk—and enter high and low search ranges for your inputs: SIMULATING THE NEW PROCESS After finding optimal input settings in the ranges you specified, Devize presents the simulated results for the recommended process changes: The simulation indicates that the new optimal settings identified will virtually eliminate out-of-spec product from your process, with a Ppk of 1.37—a vast improvement that exceeds the 1.33 Ppk standard. Thanks to you, your company’s steel products won’t be hitting any bumps in the road! GETTING GREAT RESULTS Figuring out how to improve a process is easier when you have the right tool to do it. With Monte Carlo simulation to assess process capability and Parameter Optimization to identify optimal settings, Devize can help you get there. And with Sensitivity Analysis to pinpoint exactly where to reduce variation, you can further improve your process and get the product results you need. Learn more and try Devize free at www.minitab.com/devize.
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