In this paper the problem of reconfiguration of controllers in the air control system of a bark boiler is addressed. The air control system of a bark boiler is considered as an interconnected multivariable system and the configuration of the controllers is adapted with the perspective to improve the closed loop performance of the system. The paper proposes a generic procedure for the reconfiguration of controllers using a combination of established theories together with rather recently proposed methods. The procedure is applied to a model of the air flow system, which is derived in this study. The results indicate that a significant performance improvement can be achieved by reconfiguring the control system instead of re-design the process. The improvement is quantified through theoretical assessment, simulation studies, and performance assessment of pilot tests at the bark boiler at SCA Obbola Sweden. It can be concluded that the proposed procedure is both efficient and easy to apply.