  This contribution reviews the present status of the Skyrme-Hartree-Fock (SHF)
approach as one of the leading self-consistent mean-field models in the physics
of atomic nuclei. It starts with a brief summary of the formalism and strategy
for proper calibration of the SHF functional. The main emphasis lies on an
exploration of the reliability of predictions, particularly in the regime of
extrapolations. Various strategies are discussed to explore the statistical and
systematic errors of SHF. The strategies are illustrated on examples from
actual applications. Variations of model and fit data are used to get an idea
about systematic errors. The statistical error is evaluated in straightforward
manner by statistical analysis based on $\chi^2$ fits. This also allows also to
evaluate the correlations (covariances) between observables which provides
useful insights into the structure of the model and of the fitting strategy.
