A method for providing a collaborative production scheduling system uses the internet and allows a supplier and its customers to interact with a data set that contains forecast information relating to products manufactured by the supplier and purchased by the customers. An initial forecast is provided by the supplier for each of a plurality of customers and those forecasts are made available for access by the customers. Each of the customers of the supplier is allowed to review and access the data contained in the forecast schedule at predetermined periods of time (e.g. monthly) and for preselected durations (e.g. fifteen days). During those times, all of the customers of the supplier can amend the predetermined forecast schedule based on their own estimates of their future demand for the suppliers products. The supplier then can accumulate the information obtained from its customers and schedule production at its own facilities in order to appropriately meet the anticipated demand of its customers.