This work presents a new programming language, integrated in a platform that allows creating process management applications where it is used to interpret instructions that represent flow rules associated with each of the processes. The origin of the problem, alternative solutions, and the motivation for the proposal are addressed. The characteristics of the language and the elements that compose it are described. Subsequently, the proposal is validated through a series of test cases in which the problem is solved by creating programs written in F_RULE. Finally, from the test cases, it can be seen that the proposal made adapts correctly to different typical work situations in business process management systems.