Boxed Skew Plane Partition and Integrable Phase Model

We study the relation between the boxed skew plane partition and the integrable phase model. We introduce a generalization of a scalar product of the phase model and calculate it in two ways; the first one in terms of the skew Schur functions, and another one by use of the commutation relations of operators. In both cases, a generalized scalar product is expressed as a determinant. We show that a special choice of the spectral parameters of a generalized scalar product gives the generating function of the boxed skew plane partition.