“…Wessman (1998) and Frisén et al (2011) demonstrated that if all processes have the same change points, then the univariate vector of partial likelihood ratios {L(s,t), t=1,...s}, for τ<s against τ=s, is sufficient for the sequence of distributional families. Thus, in order to monitor a simultaneous and fully specified change, it is possible to construct a univariate surveillance procedure based on the sufficient sequence of likelihood ratios.…”