In order to establish the relationship between iron casting defects and clay mould sand properties used to provide in time forecast information of casting quality, a mould sand quality control system software based on C/S model was proposed.

From the angle of systematic analysis the casting defects are regarded as systematic faults and are diagnosed and forecasted by the fault tree analysis (FTA) method.

Based on these, from the angle of systematical analysis, casting defects were regarede as systematical faults, diagnosed and forecasted by the method of microcomputer aided analysis in fault trees.