  The study of open cluster metallicities helps to understand the local stellar
formation and evolution throughout the Milky Way. Its metallicity gradient is
an important tracer for the Galactic formation in a global sense. Because open
clusters can be treated in a statistical way, the error of the cluster mean is
minimized. Our final goal is a semi-automatic statistical robust method to
estimate the metallicity of a statistically significant number of open clusters
based on Johnson BV data of their members, an algorithm that can easily be
extended to other photometric systems for a systematic investigation. This
method incorporates evolutionary grids for different metallicities and a
calibration of the effective temperature and luminosity. With cluster
parameters (age, reddening and distance) it is possible to estimate the
metallicity from a statistical point of view. The iterative process includes an
intrinsic consistency check of the starting input parameters and allows us to
modify them. We extensively tested the method with published data for the
Hyades and selected sixteen open clusters within 1000pc around the Sun with
available and reliable Johnson BV measurements. In addition, Berkeley 29, with
a distance of about 15kpc was chosen. For several targets we are able to
compare our result with published ones which yielded a very good coincidence
(including Berkeley 29).
