  A one parameter model to describe the individual metallicity distributions
and stellar mass-metallicity relation for dwarf galaxies is presented. This
multiple-burst model is based on an accretion scenario, accomodates the
observational constraint between $\overline{z}$ and $\sigma_{z}^{2}$ recently
established by Leaman (2012), and predicts a slope consistent with the stellar
mass-metallicity relation of Kirby et al (2013) who showed that the local group
dwarf spheroidal and dwarf irregular galaxies lie on the same relation. One
interpretation of the model is that it describes star formation occuring either
in gas rich mergers or at the intersection of colliding gas streams.
