Perbandingan Pengendalian Kualitas Produk Wall Display Dengan Diagram Kendali D2 dan T2 Hotelling

Abstract

Quality control is the application of statistical models of quality control to collect and analyze data to evaluate and monitor production results. Melia Frame & Calligraphy Trading Compeny is an agent and manufacturer of frames or frame bars and finished frames made from fiber and wood. The best-selling product and gets the most repeat orders is the wall display product. Although wall display are in high demand, this product has also received the most complaints and product returns due to defective products since 2023. Based on observation data, it is calculated that product defect data is quite high, namely an average total of 34 defects per day. This research aims to detecting the quality of wall display products with D2 (Mahalanobis Distance) and T2 Hotelling control charts at Melia Frame & Calligraphy Trading Company. The results of this research found that the product experienced the most defects in October 2023 with a total defective product of 1009 units. While in November and December 2023 the total defective products were 977 and 827 units. By using the control diagram, 20 observations out of a total of 75 observations are outside the control limits, then by using the control diagram, 2 observations out of a total of 75 observations are outside the control limits. This shows that the wall display production process is not under control. The most dominant type of defect found was loose assembly with 546 units (22%) of defective products. While the least defective type is broken rope with a total defective product of 218 units (9%). The results obtained from the D2 (Mahalanobis Distance) control chart show that the D2 (Mahalanobis Distance) control chart has more sensitive control limits than the T2 Hotelling control chart control limits.