Calculation of Total Cost, Tolerance Based on Taguchi’s, AsymmetricQuality Loss Function Approach

Abstract

Problem statement: Current world market force the manufacturing sectors to develop high quality product and process design with minimum possible cost. About 80% of problems in production units may be attributed to 20% of design tolerance causes. While design typically represents the smallest actual cost elements in products (around 5%), it leverages the largest cost influence (around 70%). So design engineers continuously stumble upon problem of design for high quality performance with lower cost. Objectives of this study where to: (i) simultaneous selection of design and manufacturing tolerance (ii) minimization of total cost (sum of the manufacturing cost and Taguchi's asymmetric quality cost) (iii) minimum cost and its machining tolerance. Approach: Rotor key base assembly was considered as case study to optimize the minimization of assembly total cost and machining tolerance. New global nonlinear optimization techniques called pattern search algorithm had been implemented to find optimal tolerance allocation and total cost. Results: In this study minimum cost arrived was 45.15 Cr and its corresponding tolerances for machining process turning, drilling, face milling, face milling and drilling where 0.063, 0.0508, 0.2127, 0.2127, 0.2540 mm respectively at worst case conditions. Conclusion: Results indicated that optimization by integer programming, sequential quadratic programming and exhaustive search, nonlinear programming, genetic algorithm, simulated annealing, fuzzy logic, number set theory and Monte Carlo simulation did not give much least total cost and also predicted that pattern search algorithm was robust method. Second the method, generally termed as concurrent tolerance synthesis was well suited for engineering environment, where high quality products with low total cost were designed and manufactured.

Variable Neighborhood Simplex Search Methods for Global Optimization Models

“…Generally, the average (Av), the sample Standard deviation (Sd) and the Signal to Noise ratio (SN) of actual objective function values deteriorate when there is an increase of noise on the objective function values as shown in Fig. 5-7, respectively (Lan, 2010;2011;Kumar et al, 2009). However, on all performance measures the VMSM performs better than other versions of VNSS based methods.…”

Optimal Pareto front for manufacturing tolerance allocation model

“…Under this line of reasoning, equation (22) becomes the first objective function of this model. The second objective function is same as given in equation (21) and is stated here as a minimization criterion as equation (23). Equation (24) represents that the lower dimensional limit of the pin is always above the minimum size of the pin at À3s p limits.…”

“…The manufacturing constraints are ensured through equations (24)- (29). This module calculates the total cost TC (using equation (22)) and clearance variation C v (using equation (23)) by substituting the input data given in Table 2 and the current pin and hole sizes. Calculated TC, C v and the corresponding t u h , t l h , t u p , t l p are stored and then proceeded further by updating the pin and hole sizes. Table 3 shows t u h , t l h , t u p , t l p , C v and TC at different iterations.…”

“…Kumar et al 23 discussed the use of asymmetric quality loss function approach with a rotor key assembly as an example. Jeang 24 developed a new method to find the best process means and process tolerance.…”

A Study of Parameters Relationship to Backcutting Phenomena During High Speed End Milling of AISI H13

“…Consequences of the need for good quality in manufacturing industries and in conjuction to current world market force the manufacturing sectors to develop high quality product and process design with minimum possible cost (Sampath et al, 2009) especially which applied high speed machining, various works have been conducted by researchers. Previous studies show many efforts and contributions in the effects of cutting conditions, cutting geometry and the mechanical properties of the study piece material on dimensional precision (Lou et al, 1998;Brezocnik et al, 2004;Benardos and Vosniakos, 2003.…”