Standard Practice for Conducting Ruggedness Tests

5.1 A ruggedness test is a special application of a statistically designed experiment. It is generally carried out when it is desirable to examine a large number of possible factors to determine which of these factors might have the greatest effect on the outcome of a test method. Statistical design enables more accurate determination of the factor effects than would be achieved if separate experiments were carried out for each factor. The proposed designs are easy to use and are efficient in developing the information needed for evaluating quantitative test methods.

5.2 In ruggedness testing, the two levels for each factor are chosen to use moderate separations between the high and low settings. In general, the size of effects, and the likelihood of interactions between the factors, will increase with increased separation between the high and low settings of the factors.

5.3 Ruggedness testing is usually done within a single laboratory on uniform material, so the effects of changing only the factors are measured. The results may then be used to assist in determining the degree of control required of factors described in the test method.

5.4 Ruggedness testing is part of the validation phase of developing a standard test method as described in Guide E1488. It is preferred that a ruggedness test precedes an interlaboratory (round robin) study.