# Common Oats

Topics: Software testing, Experimental design, Orthogonal array testing Pages: 4 (769 words) Published: May 8, 2013
1. Introduction
Purpose / Objective
This document, describes the concepts of Orthogonal Array Testing. The document describes the usage, benefits and limitations of Orthogonal Array Testing. This document also gives examples of how Orthogonal Array Testing can be implemented.

Scope
This is Black box testing technique which uses systematic and statistical pair-wise testing to find maximum defects with minimum test cases. Also known as OATS (Orthogonal Array testing Strategy), this is a combinatorial testing method.

The Orthogonal Arrays were originally discovered by Monks later absorbed by Statistical groups. Dr. Genichi Taguchi proposed this technique in test design and his technique was known as Taguchi Methods.

Orthogonal arrays are two dimensional arrays in which choosing any two columns in the array gives an even distribution of all the pair-wise combinations of values in the array. OATS is effective in detection of Region Faults using less number of test cases.

Orthogonal Array Terminology

An orthogonal array is a rectangular matrix which contains Runs, Factors and levels

Runs: Number of rows in the array which represents test case Factors: Number of columns in the array which represents maximum number of variables to be tested Levels: Different states that can be taken by each variable

Strength: the number of columns it takes to see each of the Levels
The underlying rationale of this technique is based on the hypothesis that almost all defects in software are due to either specific levels of a single factor or due to pair-wise interactions of factors at certain levels.

Example:
Consider a web page with three distinct sections (Top, Middle, and Bottom) that can be individually shown or hidden by the user. You wish to test the interactions of the different sections. Following the instructions laid out previously, let's create a test set for the system. 1. There are three independent variables (the sections of the page)....