PENERAPAN DIAGRAM KONTROL IMPROVED GENERALIZED VARIANCE PADA PROSES PRODUKSI HIGH DENSITY POLYETHYLENE (HDPE) (Studi Kasus Di CV. Garuda Plastik Karangawen)

Abstract

In a manufacturing industry, the appropriate quality control standards of the company against the resulting product is indispensable. In the quality control usually only use the simple method, so any further analysis is needed, that is by using one of the methods of statistical inference. Case study research at CV. Garuda Plastik Karangawen to know the circumstances of the production process of High Density PolyEthylene (HDPE). The quality control is carried out involving two characteristics of quality, that is the length and weight HDPE. The quality is generally measured using several characteristics, so that the required method of multivariate quality control in performing monitoring. The quality control mean process using control charts T^2Hotelling, while the quality control variability process using control charts Improved Generalized Variance. There are two stages of this research. In phase I the HDPE production process has not been stable in the mean and variability. In phase 2 the HDPE production process has not been stable in variability but is stable in the mean, it means the production process phase II has already made improvements. Based on it that causes can make the production process is not stable is a chase target production system so that the effect on the raw material, the engine temperature setting and often changing so that the roll size HDPE result became diverse. Keywords : quality control, mean, variability, control charts T^2Hotelling , control charts Improved Generalized Variance.