A control device of a continuous production system producing a product from a raw material by a production process having a plurality of steps including a plurality of production apparatuses configured to handle the steps; the control device is configured to determine a control target value set for at least any of the plurality of production apparatuses, wherein the control device in a preparation stage is configured to collect information of manufacturing conditions for the production process which has already been run for several lots to classify each lot, based on a cluster analysis of the principal components of the collected manufacturing conditions into a plurality of groups, with one group for each process step, to generate a plurality of routes, wherein each route corresponds to a combination of groups, wherein the combination of groups comprises one group for each process step; to inspect the failure rate of each route, and to define a product quality for each route based on the failure rate; wherein the control device in an operation stage, upon obtaining information of a property of the raw material input to the production process, is configured to: determine a control target value set for at least any of the plurality of production apparatuses by referring to the routes and their corresponding quality such that the control target values are determined according to the route where the quality is known from past production results, wherein the route represents the manufacturing conditions that are followed when a lot passes through the production process and wherein a combination of groups constitutes said route; and set the determined control target value in at least any of the plurality of production apparatuses. a plurality of production apparatuses configured to handle the steps; the control device is configured to determine a control target value set for at least any of the plurality of production apparatuses, wherein the control device in a preparation stage is configured to collect information of manufacturing conditions for the production process which has already been run for several lots to classify each lot, based on a cluster analysis of the principal components of the collected manufacturing conditions into a plurality of groups, with one group for each process step, to generate a plurality of routes, wherein each route corresponds to a combination of groups, wherein the combination of groups comprises one group for each process step; to inspect the failure rate of each route, and to define a product quality for each route based on the failure rate; wherein the control device in an operation stage, upon obtaining information of a property of the raw material input to the production process, is configured to: determine a control target value set for at least any of the plurality of production apparatuses by referring to the routes and their corresponding quality such that the control target values are determined according to the route where the quality is known from past production results, wherein the route represents the manufacturing conditions that are followed when a lot passes through the production process and wherein a combination of groups constitutes said route; and set the determined control target value in at least any of the plurality of production apparatuses. determine a control target value set for at least any of the plurality of production apparatuses by referring to the routes and their corresponding quality such that the control target values are determined according to the route where the quality is known from past production results, wherein the route represents the manufacturing conditions that are followed when a lot passes through the production process and wherein a combination of groups constitutes said route; and set the determined control target value in at least any of the plurality of production apparatuses.