Abstract:

The EPQ (economic production quantity) model of learning effect in the process of production and quality inspection is extended. The production process is not perfect, and quality defects will be produced. On the basis of constant demand, a cost function model of the learning effect in the process of production and quality screening is established, and the solution is solved by Newton method. Numerical and sensitivity analyses show that, along with the advance of production, in the early stages of production, the average production time of the unit product decreases rapidly with the increase of productivity, but the optimal production time tends to be stable in the later stage. With the increase of learning coefficient, the optimal production time decreases slowly; with the increase of the quality screening coefficient, the optimal production time increases slowly; with the increase of the defect rate, the optimal total average cost increases quickly. The conclusion provides the basis for the optimal decision.

Key words: productivity, quality inspection, learning effect, lot sizing, quality defect