This work is concerned with a methodology for impact evaluation of alternative industrial process-control strategies applied to the steam generator of a 125 MW fuel-fired thermoelectric power-plant unit. The methodology employed is described. It relies on a “systems” approach and embodies nonlinear plant modelling and simulation. The technique used to build the model is presented, as well as some comparisons between different control structures based on classical and predictive/adaptive control strategies. A case study is presented which is distinguished by the availability of a rich set of experimental data, allowing detailed model tuning and validation. The methodology followed forms a paradigm which may be applied to other types of industrial process.