  The S-matrix approach is used to calculate charged as well as neutral pion
production reactions from NN scattering, with the same set of underlying
processes and interactions. The chiral perturbation theory piN scattering
amplitude is used. For the nucleon-nucleon distortions a newly developed
realistic potential within the Bonn family of potentials, valid well above the
pion production threshold, is considered. In the pi+ production case, the NN
potential, the piN relative p-waves and the treatment of the exchanged pion
energy build up the observed cross-section strength.
