A management system for a refrigeration apparatus including a chiller unit, comprising: an instruction transmission unit configured to transmit a start instruction to a device or at least one of a plurality of devices (20, 42, 50, 52, 62, 70) included in the refrigeration apparatus; a response reception unit configured to receive a response indicating that a state transition is made by the device or the at least one of the plurality of devices in accordance with the start instruction; a detection unit configured to detect an abnormal condition in which the response is not received by the response reception unit within a reference time period after transmission of the start instruction by the instruction transmission unit; a storage unit configured to store the reference time period; a time measurement unit configured to measure a length of time from when the instruction transmission unit transmits the start instruction to when the response reception unit receives the response; a mode setting unit configured to set an operating mode of the management system to a reference-time-period calculation mode in which calculations are performed to determine the reference time period; and a calculation unit configured to perform, in the reference-time-period calculation mode, calculations to determine the reference time period based on a measurement result obtained by the time measurement unit and prompts the storage unit to store the determined reference time period, characterized in that: the state transition means that a temperature of a heat medium exchanging heat in a heat exchanger in the chiller unit and flowing out of the heat exchanger becomes a predetermined temperature due to an operation of the chiller unit; and the mode setting unit is further configured to set the operating mode to the reference-time-period calculation mode when a predetermined time period has elapsed from storing of the reference time period in the storage unit and/or at a predetermined time. an instruction transmission unit configured to transmit a start instruction to a device or at least one of a plurality of devices (20, 42, 50, 52, 62, 70) included in the refrigeration apparatus; a response reception unit configured to receive a response indicating that a state transition is made by the device or the at least one of the plurality of devices in accordance with the start instruction; a detection unit configured to detect an abnormal condition in which the response is not received by the response reception unit within a reference time period after transmission of the start instruction by the instruction transmission unit; a storage unit configured to store the reference time period; a time measurement unit configured to measure a length of time from when the instruction transmission unit transmits the start instruction to when the response reception unit receives the response; a mode setting unit configured to set an operating mode of the management system to a reference-time-period calculation mode in which calculations are performed to determine the reference time period; and a calculation unit configured to perform, in the reference-time-period calculation mode, calculations to determine the reference time period based on a measurement result obtained by the time measurement unit and prompts the storage unit to store the determined reference time period, characterized in that: the state transition means that a temperature of a heat medium exchanging heat in a heat exchanger in the chiller unit and flowing out of the heat exchanger becomes a predetermined temperature due to an operation of the chiller unit; and the mode setting unit is further configured to set the operating mode to the reference-time-period calculation mode when a predetermined time period has elapsed from storing of the reference time period in the storage unit and/or at a predetermined time. the state transition means that a temperature of a heat medium exchanging heat in a heat exchanger in the chiller unit and flowing out of the heat exchanger becomes a predetermined temperature due to an operation of the chiller unit; and the mode setting unit is further configured to set the operating mode to the reference-time-period calculation mode when a predetermined time period has elapsed from storing of the reference time period in the storage unit and/or at a predetermined time.