SPOTMisc (source package) is on CRAN:
[SPOTMisc] implements additional models, simulation tools, andBettonvil, B., and Kleijnen (1997), J. P. Searching for important factors in simulation models with many factors: Sequential bifurcation. European Journal of Operational Research 96, 1 (1997), 180–194.
interfaces as extensions to ‘SPOT‘. It provides tools for
interfacing ‘mlr‘, for performing Markov chain simulations,
and for sensitivity analysis based on sequential bifurcation
methods as described in Bettonvil and Kleijnen (1997).
Furthermore, additional plotting functions for output from
‘SPOT‘ runs are implemented.