Multivariate analysis of the effect of learning and forgetting on product quality

The impact of alternate periods of learning and forgetting on product quality in a manufacturing system is discussed in this paper. Factors that may precipitate forgetting are often recognized as interruptions in the production process. Interruptions can occur at scheduled times or randomly. The approach presented here addresses the mixed effect of learning and forgetting. The resultant output of the worker is compared with the expected output without interruption. A case model is used as an illustrative model for the proposed methodology. The approach extends the conventional univariate learning curve to a multivariate model and incorporates a forget model. Multivariate analysis facilitates the inclusion of other important factors in manufacturing productivity analysis. The inclusion of a forget model creates a realistic representation of the effects of learning and forgetting on worker output and product quality.