Method for operating a technical installation (A1-A3) with an optimal model, wherein the installation (A1-A3) is part of a system with a first technical installation and at least one second technical installation (A2, A3), each installation (A1-A3) including a control apparatus with a memory and a connected technical device and wherein the system furthermore comprises a server with a memory, wherein the following method steps (Q1-Q9) are executed: Q1) creating a basic device model with respect to at least one of the technical devices, Q2) distributing the basic device model to a first and at least one second control apparatus of the respective installations, Q3) creating, training and storing a first device model by the first control apparatus and at least one second device model (MS2, MS3) by the at least one second control apparatus (16, 17), in each case on the basis of the basic device model, Q4) providing the first and the at least one second device model (MS1-MS3) to the server and storing the first and the at least one second device model (MS1-MS3) in a model memory of the server, Q5) loading and providing at least those device models (MS2, MS3) which are not already present in the control apparatus to the corresponding control apparatus, Q6) applying the device models (MS2, MS3) provided in step Q5) to the respective control apparatus and determining a respective similarity function (SF1_2, SF1_3) with respect to the first control apparatus and a first similarity model (MS1, MS3) to the at least one second control apparatus (16, 17) and determining a respective similarity function (SF2_1, SF2_3, SF_3_1, SF3_2) with respect to the at least one second control apparatus (16, 17), Q7) transferring the respective similarity functions (SF1_2, SF1_3, SF2_1, SF2_3, SF_3_1, SF3_2) to the server, Q8) forming at least one client group and producing a respective group model (MG1-MG3) by federated learning within the client group by applying the similarity functions (SF1_2, SF1_3, SF2_1, SF2_3, SF_3_1, SF3_2) by the server, Q9) selecting and loading an operation model from the at least one group model for an installation and providing the operation model to the control apparatus thereof and actuating the corresponding device using the selected operation model as the optimal model. Q1) creating a basic device model with respect to at least one of the technical devices, Q2) distributing the basic device model to a first and at least one second control apparatus of the respective installations, Q3) creating, training and storing a first device model by the first control apparatus and at least one second device model (MS2, MS3) by the at least one second control apparatus (16, 17), in each case on the basis of the basic device model, Q4) providing the first and the at least one second device model (MS1-MS3) to the server and storing the first and the at least one second device model (MS1-MS3) in a model memory of the server, Q5) loading and providing at least those device models (MS2, MS3) which are not already present in the control apparatus to the corresponding control apparatus, Q6) applying the device models (MS2, MS3) provided in step Q5) to the respective control apparatus and determining a respective similarity function (SF1_2, SF1_3) with respect to the first control apparatus and a first similarity model (MS1, MS3) to the at least one second control apparatus (16, 17) and determining a respective similarity function (SF2_1, SF2_3, SF_3_1, SF3_2) with respect to the at least one second control apparatus (16, 17), Q7) transferring the respective similarity functions (SF1_2, SF1_3, SF2_1, SF2_3, SF_3_1, SF3_2) to the server, Q8) forming at least one client group and producing a respective group model (MG1-MG3) by federated learning within the client group by applying the similarity functions (SF1_2, SF1_3, SF2_1, SF2_3, SF_3_1, SF3_2) by the server, Q9) selecting and loading an operation model from the at least one group model for an installation and providing the operation model to the control apparatus thereof and actuating the corresponding device using the selected operation model as the optimal model.