The resolution of complex design problems requires a distributed design system that considers the involvement of various designers. Inconsistencies of design objectives and working procedures of distributed subsystems can cause design conflicts due to couplings among their subproblems. Another issue is the management of imprecision in design systems caused by the lack of knowledge about the final decision. In this paper, we define a conflict management model using the concept of set-based design to overcome these issues. We utilize constraint satisfaction problem (CSP) techniques and model agent attitudes to detect and justify design conflicts of heterogeneous design agents. A novel cooperative CSP is defined for resolving design conflicts through compromising constraint restriction. The conflict resolution system can be adopted with different strategies which take into account the solidarity architecture of design agents. The gains and costs of centralized, decentralized and controlled conflict resolution system strategies are simulated with the Monte Carlo method where design agent characters and their interactions reflect a stochastic nature.