A business process is a collection of structured tasks corresponding to a service or a product. Business processes do not execute once and for all, but are executed multiple times resulting in multiple instances. In this context, it is particularly difficult to ensure correctness and efficiency of the multiple executions of a process. In this paper, we propose to rely on Probabilistic Model Checking (PMC) to automatically verify that multiple executions of a process respect some specific probabilistic property. This approach applies at runtime, thus the evaluation of the property is periodically verified and the corresponding results updated. However, we go beyond runtime PMC for BPMN, since we propose runtime enforcement techniques to keep executing the process while avoiding the violation of the property. To do so, our approach combines monitoring techniques, computation of probabilistic models, PMC, and runtime enforcement techniques. The approach has been implemented as a toolchain and has been validated on several realistic BPMN processes.