The Weyerhaeuser digester problem (WDP) is a simplified digester model which captures the major dynamic characteristics of a continuous pulp digester and has been offered to the research community as an industrial challenge problem. The control objective is to minimize variations in the Kappa # for unmeasured disturbances. A systematic approach to selecting the manipulated inputs and secondary measurements using robust control analysis tools has been successfully applied to the WDP. A multi-rate data-sampling linear model predictive controller using the selected input/measurement pairings provided robust closed-loop performance for the rejection of both deterministic and stochastic unmeasured disturbances.