Abstract: This invention relates to a method, a program, and a system for the determination of the proper number of workers to staff a production line. The invention provides a periodical production plan, a capacity model, and a production worker performance database. The database includes both the time required for a worker to perform activities prior to and following the worker activating a tool for processing a semi-product. The number of worker to staff the production line properly is generated with the method. Actual performance data are collected to update the worker performance database.