Forecasting ​related time series using Granger's causality

Point of sales (POS) is the data that is recorded at the retailer level when consumers purchase the products.  POS data is becoming increasingly popular for companies to predict their sales. In a supply chain, the POS data are often used by retailers to predict their sales, however, manufacturers and suppliers have not benefited enough from POS data. Retailers place their orders to suppliers as they predict their sales.

The goal is to predict the supplier's demand. We can use either the retailer's orders or POS data to forecast suppliers' demand. The idea is to use Granger's causality​​ to forecast ​one time series​ (suppliers demand)​ from ​another​ time series​ (POS data)​. This is an empirical study and we will be using real sales time series​​ of food company.