A method of producing phenol and acetone can comprise: alkylating benzene with a C 2-6 alkyl source in the presence of a zeolite catalyst to produce a C 8-12 alkylbenzene; oxidizing the C 8-12 alkylbenzene in the presence of an oxygen containing gas to produce a C 8-12 alkylbenzene hydroperoxide; cleaving decomposing the C 8-12 alkylbenzene hydroperoxide in the presence of an acid catalyst to produce phenol, a C 3-6 ketone, and undesirable side products such as, but not limited to acetaldehyde, DMBA, acetophenone, AMS, AMS dimers, unidentified heavies, or a combination comprising at least one of the foregoing; and monitoring a concentration of the C 8-12 alkylbenzene hydroperoxide in a process stream of a reactor in real time at a temperature and a pressure of the process stream; and in real time, controlling a parameter of the reactor and/or the cleaving decomposing in response to the concentration of the C 8-12 alkylbenzene hydroperoxide.