A process and system for monitoring and controlling the operation of a dehydrogenation reactor is provided. Samples of hydrocarbon streams are taken at sampling locations to be analyzed at a single gas chromatograph or other analytical equipment. Actions can be taken to modify the operation of the dehydrogenation reactor as necessary to maintain its operation within predetermined parameters. In particular, actions may be taken when a hydrocarbon stream exhibits an amount of cracking that is outside parameters. It is usually intended that actions will be taken on a gradual basis once or twice per day to reduce the cost of the process while still providing the necessary changes to operations.