This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial applicationsin the process industry. The paper addresses the fact that dynamic performance of the system is important, to ensure optimal changes between different operation conditions. To enable optimisation of the dynamic controller behaviour a method for designing the required excitation signal is presented. Furthermore, invasive weed optimisation is used to find the optimal parameters for local controllers based on the plant wide performance measure.