1. A method, comprising: implementing a segregated data structure including a plurality of items in an APC controller, each item of said segregated data structure representing a manufacturing context of a manufacturing environment controlled by said APC controller; determining a threshold criterion for at least one manufacturing context, said threshold criterion indicating, when fulfilled, an insufficiency of data available for said at least one manufacturing context; comparing, by said APC controller, a current manufacturing context of a substrate to be processed in said manufacturing environment with said threshold criterion; and when said current manufacturing context corresponds to said at least one manufacturing context and said threshold criterion is fulfilled, estimating a controller state for said current manufacturing context on the basis of one or more of the plurality of manufacturing contexts other than said at least one manufacturing context.