Abstract :
PT. Kasai Teck See is a car spare parts provider company experiencing
problems if consumer demand is received simultaneously. Because the
production machine has the maximum capacity to do production everyday. This
will result in the process of sending goods being hampered because the
production process is still not finished. This is why PT. Kasai want to study the
historical pattern of sales to consumers so that it becomes a reference for the
future. In the process of processing so far PT. Kasai only uses Microsoft Excel.
Fuzzy Mamdani method can be used to make sales predictions using historical
sales data of PT. Kasai Teck See. Sales data used for the Mamdani calculation
is sales data of PT. Kasai in 2017 and 2018. The data used for the discussion of
this method is to use demand data totaling 4000 and inventory totaling 300.
Sales prediction results obtained in the amount of 4247 units. With an accuracy
rate of 95.8791% using MAPE