Method for supervising product properties and method for controlling a manufacturing process

摘要

The manufacturing process is monitored by relating product properties to process data by means of a forecasting model which gives at least one prediction with a confidence limit range. Process data is continually measured and stored and compared with the boundary values for which the model is valid. When process data fall outside the valid range, product properties are measured and recorded. If the measured properties are outside the confidence limits of the predictions of the model. the model is amended accordingly. Also claimed is a corresp. procedure for controlling a process where the model is used to predict the result of a control action.