runs

A set of process conditions defined by specifying levels of all the factors in the experiment.

The number of runs is the number of rows in the basic Taguchi orthogonal array. It tells you the number of distinct factor combinations to be run in the experiment.

Suppose you have a design with 3 factors with 2 levels each:

1    1    1

1    2    2

2    1    2

2    2    1

For the second run (located in second row), you would set Factor A low, Factor B high, and Factor C high.