When the information from the factory floor is made available to departments outside manufacturing - purchasing, for instance, or sales - it can be put to productive use. Constant awareness of inventory levels is an absolute necessity if a plant wants to move toward Just-in-time. Similarly, good control over output is important for companies that want to build to order, or minimize warehousing of finished goods. Before these benefits can be realized, changes must occur throughout the factory. Electronic systems in the plant must be enhanced in order to yeild the three Rs of real-time systems: response, resiliency, and reliability. Controllers and minicomputers in the factory must be tied together and then linked to computers in data processing departments. The closer the ties, the faster the movement of information, and the more efficient the factory can become.