Ivan Pudjihardjo, Ig. Jaka Mulyana, Luh Juni Asrini
In this article will be discussed about the implementation of control chart in cooking oil industry. Cooking oil has some parameters of quality i.e. Free Fatty Acid (FFA), Peroxide Value (PV), Iodine Value (IV), color (Red and Yellow), Moisture Content, Cloud Point (CP), Cloud Stability (CS) and Freezing Point. The observed data of cooking oil quality parameters shows that the data is autocorrelated. Therefore, residual mapping based on forecasting results from the time series model is used to construct autocorrelated multivariate control chart. In the multivariate T2 Hotelling control chart of the residual VAR model (2) for chemical factor has a upper control limit (UCL) value of 22.18 and a median of 3.60. The T2 Hotelling control chart of the residual VAR model (2) for physical factors has a control upper control limit (UCL) of 21.59 and a median value of 3.63. © IEOM Society International.
Industrial Engineering Department, Widya Mandala Surabaya Catholic University, Jl. Kalijudan 37, Surabaya, Indonesia