We present a fully calibrated model for the diffusion, segregation, and activation of phosphorus for typical annealing conditions of implanted silicon solar cells. In contrast to existing process simulation software, this model allows the quantitative prediction of doping profile distributions, and, thereby, sheet resistances, surface concentrations, and junction depths. The model also provides an intuitive understanding of the dependence of these quantities on the parameters of the annealing process. A post-print version of the article can be found at publica.fraunhofer.de/documents/N-322023.html