Many recent works show that copulas turn out to be useful in a variety of different ap-
plications, especially in environmental sciences. Here the variables of interest are usually
continuous, being times, lengths, weights, and so on. Unfortunately, the corresponding
observations may suffer from (instrumental) rounding and adjustments, and eventually
they may show several repeated values (i.e., ties). In turn, on the one hand, a tricky
issue of identifiability of the model arises, and, on the other hand, the assessment of the
risk may be adversely affected. A possible remedy is to introduce suitable randomization
procedures: here three different jittering strategies are outlined. The target of the work is to carry out a simulation study in order to evaluate the effects of the randomization
of multivariate observations when ties are present. In particular, it will be investigated
whether, how, and to what extent, the randomization may change the estimation of the
structural risk: for this purpose, a coastal engineering example will be used, as archetypical of a broad class of models and problems in engineering practice. Practical advices
and warnings about the use of randomization techniques are hence given.
