MES與質檢分類

MES and Quality Inspection and Sorting

質 檢分類 (Quality Inspection and Sorting) 是指根據產品品質進行分類的過程。這種手法具有多方面的好處，可以將不同品質的產品進行有效分類，根據不同的品質標準重新定義料號，從而滿足不 同客戶的需求。通過這種精細的分類，企業可以將高品質產品賣給對品質要求高的客戶，同時將次級產品以較低價格提供給對品質要求較低的市 場。這不僅能提高產品的整體價值，還能減少不良品的浪費和損失。在台灣，許多工廠已經實踐這種方法，因為它能有效解決生產品質不穩定的現 象，提高生產效率和產品合格率，最終增強企業在市場上的競爭力。

今 天，是否我們可以把這種生產方式透過MES系 統輔助，使用兩個控制界限 (Control Limits) 來 更精確地挑選產品，並決定其最終料號？這問題的答案是“技術上可行，但實務上不建議”。誠然，當今的MES系 統具有強大的輔助能力，可以滿足品質管理的需求。通過整合SPC的 兩個控制界限 (Control Limits)，MES系 統能夠自動化地對產品進行最終料號的判別。

雖 然MES可 以輔助這種生產方式，但鮮少MES系 統會具備這種功能。主要原因是這種作法違反了全面品質管理 (TQM) 的 精神。TQM 強 調全程參與和持續改進，要求在產品設計、製造過程和交付過程的每一個階段進行品質控制，而不是僅僅依賴最終成品的檢驗。TQM 注 重的是預防性品質控制和全員參與，確保每個環節都符合品質標準，從而減少浪費和提高效率。僅在最終階段進行質檢和料號判別，忽視了生產過 程中的品質管理，這不符合 TQM 的 核心理念，導致品質問題可能在早期階段未被發現並及時解決。

從 精實管理 (lean manufacturing) 的 角度來看，如果讓參與生產管理的所有人都認為品質問題可以在最後解決，那麼之前所有製程的持續改進 (continuous improvement) 重 心將會偏向於提高產能而非解決品質問題。精實管理的精神是強調減少浪費和持續改進生產過程中的每個階段，以提高整體效率和產品品質。如果 所有人都認為最終檢驗可以解決品質問題，他們很自然地會忽視前段生產過程中的潛在問題和瑕疵，導致這些問題累積並影響最終產品的品質。此 外，這種思維會使生產團隊專注於提高生產速度和產量，而忽視了過程中的品質控制和改進，這違背了精實管理中“品質優先”和“每個過程都應 該完美”的核心理念。最終，這不僅無法提升產品品質，還可能增加返工和浪費的成本，損害企業的競爭力。

Quality Inspection and Sorting (QIS) categorizes products based on quality, meeting diverse customer needs and enhancing product value. It reduces waste, minimizes losses from defective products, and has been successfully implemented in many Taiwanese factories. While integrating QIS with MES and dual Control Limits can enhance precision, it conflicts with Total Quality Management (TQM) and Lean Manufacturing principles. TQM emphasizes full participation and continuous improvement, requiring quality control at all stages. Lean Manufacturing focuses on reducing waste and improving processes, not just final inspections. Therefore, most MES systems do not support this function, prioritizing comprehensive quality monitoring and continuous improvement instead.

Quality Inspection and Sorting refers to the process of classifying products based on their quality. This method has multiple benefits, allowing for effective categorization of products according to different quality standards and redefining item numbers to meet various customer needs. Through this precise sorting, companies can sell high-quality products to customers with stringent quality requirements, while offering lower-quality products at lower prices to markets with less stringent requirements. This not only enhances the overall value of the products but also reduces waste and losses from defective products. In Taiwan, many factories have already implemented this method because it effectively addresses the issue of inconsistent production quality, improves production efficiency, and increases product pass rates, ultimately strengthening the company's competitiveness in the market.

Today, can we use this production method with the assistance of MES (Manufacturing Execution System) to more accurately select products and determine their final item numbers by using two Control Limits? The answer is "technically feasible, but not recommended in practice." Indeed, modern MES systems have powerful auxiliary capabilities that can meet quality management needs. By integrating the two Control Limits of SPC (Statistical Process Control), MES systems can automatically determine the final item numbers of products.

Although MES can assist this production method, few MES systems have this function. The main reason is that this approach violates the principles of Total Quality Management (TQM). TQM emphasizes full participation and continuous improvement, requiring quality control at every stage of product design, manufacturing, and delivery, rather than relying solely on final product inspection. TQM focuses on preventive quality control and full participation, ensuring that each link meets quality standards, thereby reducing waste and increasing efficiency. Relying only on final inspection and item number determination ignores quality management during the production process, which does not align with the core principles of TQM. This can lead to quality issues not being detected and addressed early.

From the perspective of Lean Manufacturing, if all those involved in production management believe that quality issues can be resolved at the end, then the focus of all previous processes' continuous improvement will shift towards increasing production capacity rather than solving quality problems. Lean Manufacturing emphasizes reducing waste and continuously improving every stage of the production process to enhance overall efficiency and product quality. If everyone believes that final inspection can resolve quality issues, they will naturally ignore potential problems and defects in the earlier production stages, causing these issues to accumulate and affect the final product quality. Moreover, this mindset will make production teams focus on increasing production speed and quantity, neglecting quality control and improvement during the process, which contradicts the Lean Manufacturing principles of "quality first" and "every process should be perfect." Ultimately, this not only fails to improve product quality but also increases rework and waste costs, harming the company's competitiveness.