Advancing information technologies are increasing the evolution and variation of software resources. Applications that cannot adapt to dynamic environments will decrease their usefulness, particularly to business process systems that face requirements changed frequently. After surveying related work, we propose a new formalism for modeling Dynamic Process in which the state space and transition function are enriched so that one model can transit to another model at runtime by the computational reflection that aims to represent and modify its own design. Such goal necessitates an appropriate runtime environment. We introduce the Service Cooperation Middleware (SCM) because it is service-oriented, into which the reflection mechanism is easily attached to support structural and behavioural changes on processes at runtime.