The quality of a product has become an essential component in today's international market-place. In manufacturing systems operating under a ‘no-defects’ quality-control policy, locating the origin of any imperfections must be implemented by placing several inspection stations within the production process. In this paper an aggregate manufacturing-inspection system model which represents a no-defects control policy is presented. The model can be used to qualitatively predict the effect of inspection on product quality under several different system configurations and hence can be used as a design tool as well as a quality-control tool.