This paper proposes a novel framework that integrates production planning and quality control within a context of continuous improvement. Process degradation is jointly monitored using X-bar control chart, which ensures process stability monitoring, along with an anomaly index designed to assess the overall health condition of the process and, consequently, the conformity risk of outgoing products. Unlike standard control charts that only signal out-of-control conditions, the proposed anomaly index enables early degradation assessment and supports proactive decision-making before process failure occurs. An in-depth analytical investigation is conducted to identify the root causes of degradation, distinguishing between machine-related and human-related sources. Considering a finite planning horizon, an analytical economic optimization model is developed. First, it determines the production plan with the minimum average cost. Then, it maximizes the total expected profit over the planning horizon by jointly finding the optimal values of the quality-related decision variables and the appropriate improvement actions, including both imperfect and perfect actions applied according to the identified causes of degradation. A numerical example is presented to illustrate the proposed approach. The results demonstrate the framework's effectiveness in monitoring the process, addressing the root causes of degradation, and maximizing profitability.

Keywords

Process health, Production, Quality, Process degradation, Continuous improvement