  We extend the deformation theory algorithm of matrix factorizations to
systems with more than one D-brane. The obstructions to the deformations are
F-term equations which can be integrated to an effective superpotential. We
demonstrate the power of this formalism for several examples of minimal models
with two or three D-branes. These are realistic toy examples for systems with
multiple D-branes in Calabi-Yau threefolds since both classes of models have
obstructed open moduli.
