Make or Buy Analysis Model Based on Tolerance Design to Minimize Manufacturing Cost and Quality Loss

Abstract Tolerance design bridges design and manufacturing. Concurrent design of tolerances and manufacturing processes may ensure the manufacturability, reduce the manufacturing and other related costs, decrease the number of fraction nonconforming (or defective rate), and shorten the production lead time. Since process capability indices relate tolerance specifications to manufacturing process capabilities, it is quite natural to apply them to concurrent design of tolerances and processes. As process shifts often exist in a manufacturing process, using Cp does not yield a good estimation of fraction nonconforming. Index Cpk does not precisely measure process shift either, but Cpm does. Therefore, this research compares the applications of Cp, Cpk and Cpm based on a numerical example of non-linear mechanical tolerance synthesis. In addition, the Taguchi quality loss function is used together with the manufacturing cost as the objective function.

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Concurrent Tolerance Design Based on Manufacturing Cost and Quality Loss

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.687-691.4996 ◽

2014 ◽

Vol 687-691 ◽

pp. 4996-4999

Author(s):

Zhang Rong

Keyword(s):

High Performance ◽

Low Cost ◽

Engineering Application ◽

Manufacturing Cost ◽

Tolerance Design ◽

Quality Loss ◽

Product Loss ◽

Parameterized Model ◽

The Cost ◽

Design And Manufacture

With the constraints on manufacturing capacity, the satisfaction of product performance and the cost of manufacture are contradictory, the problem between high-performance and low-cost must be solved at the period of design and manufacture for product. To solve this problem, the product loss model has been analyzed, the parameterized and non-parameterized model of anticipant losses has been researched, with concurrent design, in connection with the product with multiple correlated assembly functional dimensions, the relation function between quality loss and process dimension tolerance has been provided, the concurrent tolerance design mathematical model based on lowest-cost and quality loss has been established. The applied case shows that this method has important guiding significance for engineering application.

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Component tolerance design for minimum quality loss and manufacturing cost

Computers in Industry ◽

10.1016/s0166-3615(97)00087-0 ◽

1998 ◽

Vol 35 (3) ◽

pp. 223-232 ◽

Cited By ~ 43

Author(s):

Chin-Chung Wu ◽

Zhuoning Chen ◽

Geo-Ry Tang

Keyword(s):

Manufacturing Cost ◽

Tolerance Design ◽

Quality Loss ◽

Minimum Quality

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Robust Tolerance Design With the Integer Programming Approach

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2831193 ◽

1997 ◽

Vol 119 (4A) ◽

pp. 603-610 ◽

Cited By ~ 45

Author(s):

Chang-Xue (Jack) Feng ◽

A. Kusiak

Keyword(s):

Integer Programming ◽

Loss Function ◽

Programming Approach ◽

Manufacturing Cost ◽

Tolerance Design ◽

Quality Loss ◽

Quality Loss Function ◽

The Cost ◽

Manufacturing Yield ◽

Selection Of

The quality loss function incorporates the cost of tolerances, however, it does not consider the manufacturing cost and design constraints. In this paper, a stochastic integer programming (SIP) approach is presented for simultaneous selection of tolerances and manufacturing processes. A direct link between the minimum manufacturing cost and the required level of manufacturing yield is established through the process capability index Cpk. As the tolerances in SIP are discrete, the solution generated is acceptable for manufacturing. It is shown that the integer programming models are applicable in the quality loss function and six sigma design approaches. The SIP approach is illustrated with a classical example of nonlinear tolerance design. The comparison of the proposed SIP approach, the Taguchi method, and the conventional mathematical models in tolerance synthesis is presented.

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