Orthogonal arrays are used widely in manufacturing and high-technology industries for quality and productivity improvement experiments. For reasons of run size economy or flexibility, nearly orthogonal arrays are also used. The construction of orthogonal or nearly orthogonal arrays can be quite challenging. Most existing methods are complex and produce limited types of arrays. This article desc...

(say) is called symmetric, otherwise, the array is said to be asymmetric. Several methods of construction of symmetric as well as asymmetric OAs are available in the literature. Some important methods will be discussed here. One of the principal applications of the OAs is in the selection of level combinations for fractional factorial experiments. An OA of strength t is equivalent to an orthogo...

we use many kinds of combinations of raw materials and production levels in producing composite materials. testing all the states are difficult or even impossible. taguchi method is a numerical method which predicts optimum state of composite materials using special orthogonal arrays. in this research we have discussed useablity of this method and its’ potential in finding optimum mix design of...

A general method for constructing asymmetric orthogonal arrays of arbitrary strength is proposed. Application of this method is made to obtain several new families of tight asymmetric orthogonal arrays of strength three. A procedure for replacing a column with 2 symbols in an orthogonal array of strength three by several 2-symbol columns, without disturbing the orthogonality of the array, leads...

We propose a novel method for the construction of orthogonal arrays. The algorithm makes use of the Kronecker Product operator in association with unit column vectors to generate new orthogonal arrays from existing orthogonal arrays. The effectiveness of the proposed algorithm lies in the fact that it works well with any linear seed orthogonal array without imposing any constraints on the stren...

We propose a novel method for the construction of orthogonal arrays. The algorithm makes use of the Kronecker Product operator in association with unit column vectors to generate new orthogonal arrays from existing orthogonal arrays. The effectiveness of the proposed algorithm lies in the fact that it works well with any linear seed orthogonal array without imposing any constraints on the stren...

It is well-known that all orthogonal arrays of the form OA(N, t+1, 2, t) are decomposable into λ orthogonal arrays of strength t and index 1. While the same is not generally true when s = 3, we will show that all simple orthogonal arrays of the form OA(N, t + 1, 3, t) are also decomposable into orthogonal arrays of strength t and index 1.

A generalization of orthogonal arrays, namely cluster orthogonal arrays (CLOA), is introduced and some properties and construction methods are studied. The universal optimality of the fractional factorial designs represented by cluster orthogonal arrays is proved.