Add to ORKGWe first present a probabilistic version of ACP that rests on the principle that probabilistic choices are resolved before choices involved in alternative composition and parallel composition are resolved and then extend this probabilistic version of ACP with a form of interleaving in which parallel processes are interleaved according to what is known as a process-scheduling policy in the field of operating systems. We use the term strategic interleaving for this more constrained form of interleaving and the term interleaving strategy for process-scheduling policy. The extension covers probabilistic interleaving strategies