A framework to evaluate the performance of alternative management strategies taking fleet behaviour and uncertainties in biological and economic data into account, is suggested. The evaluation framework incorporates an underlying system model generating the dynamics of the simulated structure, and a perceived system model which is an assessment-prediction model used to evaluate the state of the underlying system and to specify the fishery tactics. Biological and economic data from the shrimp (Pandalus borealis) fishery in the Davis Strait, is applied to the model. The study demonstrates that the long-term performance of the fishery tactics may deteriorate significantly if they are modified by implementation errors, exemplified by high-grading of catches, or by a political TAC setting process giving weight both to the biological advice and requests based on profit of prior years of fishing put forward by the fishery sector. In both cases the loss, expressed as a decrease in net present value of 10 years resource rent, may be greater than the loss due to incomplete knowledge of the underlying system structure.