No abstract

Purpose Scatter in the outcome of repeated experiments is unavoidable due to measurement errors in addition to the non-linear nature of the output responses with unknown influential input parameters. It is a standard practice to select an orthogonal array in the Taguchi approach for tracing optimum input parameters by conducting a few number of experiments and confirm them through additional experimentation (if necessary). The purpose of this paper is to present a simple methodology and its validation with existing test results in finding the expected range of the output response by suggesting modifications in the Taguchi method. Design/methodology/approach The modified Taguchi approach is proposed to find the optimum process parameters and the expected range of the output response. Findings This paper presents a simple methodology and its validation with existing test results in finding the expected range of the output response by suggesting modifications in the Taguchi method. Research limitations/implications Adequacy of this methodology should be examined by considering the test data on different materials and structures. Originality/value The introduction of Chauvenet’s criterion and opposing the signal-to-noise ratio transformation on repeated experiments of each test run will provide fruitful results and less computation burden.

Because of measurement errors and unknown influential input process parameters, unavoidable scatter can be expected in the nonlinear output response of repeated experiments. The Taguchi method suggests an orthogonal array for identifying optimum input process parameters by performing a few tests and confirming through experiments (if necessary). This article provides a simple methodology and its validation by tracing the optimum gas metal arc welding (GMAW) process parameters on the %weld dilution of ST-37 steel plates. It is possible to specify the expected range of the weld dilution for the GMAW process parameters.

In this paper, an empirical study of second order rotatable designs under tri-diagonal correlated structure of errors using incomplete block designs like pairwise balanced designs (PBD) and symmetrical unequal block arrangements (SUBA) with two unequal block sizes are suggested. Further we study the variance function of the estimated response for different values of tri-diagonal correlated coefficient (ρ) and distance from center (d) for 6≤v≤15 (vnumber of factors)).

In this paper, a study on second order slope rotatable designs under intra-class correlation structure of errors using pairwise balanced designs is suggested. Further, the variance function of the estimated slopes for different values of intra-class correlated coefficient ‘ ’ for 6 ≤ v ≤ 15 (v- number of factors) are studied.