Abstract: Quality evaluation decision problem in outsourcing is studied under different information backgrounds.Quality profit models are set up with regards to buyer as principal and supplier as agent.Focus is on the study of decision problem turned into optimal control problem under asymmetric information.Maximum principle is used to get the solution to quality evaluation when supplier prevention information is hidden and simulation calculation is done.Simulation results under different information backgrounds are analyzed and compared.

Key words: asymmetric information, supply chain, principal agent, maximum principle, quality prevention, quality evaluation