Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Chapter 36 Quality Assurance, Testing, and Inspection

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Life Expectancy of Some Products

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Deming’s 14 Points

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Example of Robust Design Figure 36.1 A simple example of robust design. (a) Location of two mounting holes on a sheet-metal bracket where the deviation keeping the top surface of the bracket from being perfectly horizontal is ±α. (b) New location of holes where the deviation (keeping the top surface of the bracket from being perfectly horizontal) is reduced to ±α/2.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Taguchi Loss Function in Television Sets Figure 36.2 (a) Objective-function value distribution of color density for television sets. (b) Taguchi loss function showing the average replacement cost per unit to correct quality problems. Source: Courtesy of G. Taguchi.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Frequency Distributions Figure 36.3 (a) A histogram of the number of shafts measured and their respective diameters. This type of curve is called a frequency distribution. (b) A normal distribution curve indicating areas within each range of standard deviation. Note: The greater the range, the higher is the percentage of parts that fall within it.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Frequency Distribution Curve Figure 36.4 Frequency distribution curve showing lower and upper limits.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Statistical Quality Control Charts Figure 36.5 Control charts used in statistical quality control. The process shown is in good statistical control because all points fall within the lower and upper control limits. In this illustration, the ample size is 5, and the number of samples is 1.5.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Constants for Control Charts

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Control Charts Figure 36.6 Control charts. (a) Process negins to become out of control because of such factors as tool wear (drift). The tool is changed and the process is then in statistical control. (b) Process parameters are not set properly; thus, all parts are around the upper control limit (shift in mean). (c) Process becomes out of control because of factors such as a change in the properties of the incoming material (shift in mean).

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Unstable and Stable Processes Figure 36.7 Illustration of processes that are (a) unstable or out of control and (b) stable or in control. Note in sketch (b) that all distributions have lower standard deviations and have means closer to the desired value. Source: After K. Crow.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Operating-Characteristics Curve used in Acceptance Sampling Figure 36.8 A typical operating-characteristics curve used in acceptance sampling. The higher the percentage of defective parts, the lower is the probability of acceptance by the consumer. There are several methods of obtaining these curves.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Liquid-Penetrant Inspection Figure 36.9 Sequence of operations for liquid-penetrant inspection to detect the presence of cracks and other flaws in a workpiece. Source: Metals Handbook, Desk Edition. Copyright © 1985, ASM International, Metals Park, Ohio. Used with permission.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Magnetic-Particle Inspection Figure Schematic illustration of magnetic-particle inspection of a part with a defect in it. Cracks that are in a direction parallel to the magnetic field (such as in A) would not be detected, whereas the others shown would. Cracks F, G, and H are the easiest to detect. Source: Metals Handbook, Desk Edition, Copyright © 1985, ASM International, Metals Park, Ohio. Used with permission.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Radiographic Inspection Methods Figure Three methods of radiographic inspection: (a) conventional radiography, (b) digital radiography, and (c) computed tomography. Source: Courtesy of Advanced Materials and Processes, November ASM International.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Eddy-Flow Current Changes Figure Changes in eddy-current flow caused by a defect in a workpiece. Source: Metals Handbook, Desk Edition, Copyright © 1985, ASM International, Metals Park, Ohio. Used with permission.

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R. Schmid. ISBN © 2006 Pearson Education, Inc., Upper Saddle River, NJ. All rights reserved. Basic Optical System for Detecting Flaws in Radiography Figure Schematic illustration of the basic optical system used in holography elements in radiography for detecting flaws in workpieces. Source: Metals Handbook, Desk Edition. Copyright © 1985, ASM International, Metals Park, Ohio. Used with permission.