It is advantageous to switch an active element with a background element. By using a switching mechanism, a background element can be made active while the application remains active. That is, the application does not need to be taken offline to switch the active element with a previously loaded background element. Single input/single output (SISO) relationships are defined for background elements and an active element which provides one or many functions and an active element which provides one or many functions between one input variable and one output variable. The switching mechanism acts on a given SISO relationship to determine the background element to use to replace the active element.