An approach to formally qualify commercial RTOS for safety application

Every complex and powerful system we see around us are real time embedded systems. They are real time because they are intended to respond within the time limits. In safety critical embedded systems like medical, railways, nuclear, space and aerospace we need qualified hard Real Time Operating System (RTOS) as failure to deliver timely results in catastrophe. Some of the qualified RTOS for critical applications are VxWorks, DEOS. The drawback of these RTOS´s is that they are highly expensive; unavailability of complete documentation, custom built, and has limited configurability. Instead, industries use COTS (Commercially off the Shelf) RTOS which they can use, configure and qualify reduced cost. However since qualifying these RTOS for as per industry standard is a challenging task and traditional verification techniques may not be sufficient and are time consuming, formal methods can prove to be most effective & precise way of verifying the RTOS to qualify it for use in safety critical applications. This paper discusses and provides guidelines for development and implementation of formal approach to qualify a COTS RTOS as per the civil aerospace standard RTCA DO-178C.