Analyzing a controller of a power distribution unit using formal methods

This paper reports on the steps to formally verify the behavior of a controller of a power distribution unit (PDU) using the Analytical Software Design (ASD) method. The controller of the underlying PDU mainly controls the distribution of power and related network messages to a number of attached PCs and devices of X-ray systems. The behavioral correctness of the controller is critical in order to provide the clinical users the expected behavior of the system. As a result of the behavioral verification, two previously unrevealed errors were identified within the design of the PDU controller. According to the development team of the PDU the work has had a major benefit, locating errors that would have been hard to find otherwise by traditional testing.