# Orthogonal array testing

This article may be too technical for most readers to understand. (May 2021) |

**Orthogonal array testing** is a black box testing technique that is a systematic, statistical way of software testing.^{[1]}^{[2]} It is used when the number of inputs to the system is relatively small, but too large to allow for exhaustive testing of every possible input to the systems.^{[1]} It is particularly effective in finding errors associated with faulty logic within computer software systems.^{[1]} Orthogonal arrays can be applied in user interface testing, system testing, regression testing, configuration testing and performance testing.
The permutations of factor levels comprising a single treatment are so chosen that their responses are uncorrelated and therefore each treatment gives a unique piece of information. The net effects of organizing the experiment in such treatments is that the same piece of information is gathered in the minimum number of experiments.

## Background[edit]

### Orthogonal vector[edit]

Orthogonal vectors exhibit orthogonality. Orthogonal vectors exhibit the following properties:

- Each of the vectors conveys information different from that of any other vector in the sequence, i.e., each vector conveys unique information therefore avoiding redundancy.
- On a linear addition, the signals may be separated easily.
- Each of the vectors is statistically independent of the others, i.e., the correlation between them is nil.
- When linearly added, the resultant is the arithmetic sum of the individual components.

## Technique[edit]

^{[3]}

## Benefits[edit]

- Testing cycle time is reduced and analysis is simpler.
- Test cases are balanced, so it's straightforward to isolate defects and assess performance. This provides a significant cost savings over pair-wise testing.

## References[edit]

- ^
^{a}^{b}^{c}Pressman, Roger S (2005).*Software Engineering: A Practitioner's Approach*(6th ed.). McGraw-Hill. ISBN 0-07-285318-2. **^**Phadke, Madhav S. "Planning Efficient Software Tests". Phadke Associates, Inc.Numerous articles on utilizing Orthogonal Arrays for Software and System Testing.

**^**Dustin, Elfriede. "Orthogonally Speaking" (PDF). (subscription required)^{[dead link]}

## External links[edit]

- Rao, Calyampudi Radhakrishna (2009). "Orthogonal arrays".
*Scholarpedia*.**4**(7): 9076. Bibcode:2009SchpJ...4.9076R. doi:10.4249/scholarpedia.9076. - Delius, Gustav W (May 2004). "Orthogonal Arrays (Taguchi Designs)". University of York.
- Kuhfeld, Warren F. "Orthogonal Arrays". SAS Institute Inc.
SAS provides a catalog of over 117,000 orthogonal arrays.

- Phadke, Madhav S. "Planning Efficient Software Tests". Phadke Associates, Inc.
Numerous articles on utilizing Orthogonal Arrays for Software and System Testing.

- "rdExpert Software for Orthogonal Array Testing". Phadke Associates, Inc. Archived from the original on 2011-01-14.
Commercial toolset for Orthogonal Array Testing.