Towards Structuring System Specifications with Time Bands Using Layers of Rely-Guarantee Conditions

The overall specification of a cyber-physical system can be given in terms of the desired behaviour of its physical components operating within the real world. The specification of its control software can then be derived from the overall specification and the properties of the real-world phenomena, including their relationship to the computer system’s sensors and actuators. The control software specification then becomes a combination of the guarantee it makes about the system behaviour and the real-world assumptions it relies upon.