Systems, methods and devices are provided, which can include an engineering change order (ECO) base. A base layout cell includes metal layer regions, conductive gate patterns arranged above metal layer regions; oxide definition (OD) patterns, metal-zero layer over oxide-definition (metal-zero) patterns, at least one cut metal layer (CMD) pattern; and at least one via region. The base layout cell can be implemented in at least two non-identical functional cells. A first functional cell of the at least two non-identical functional cells includes first interconnection conductive patterns arranged connecting metal-zero structures corresponding to at least two metal-zero patterns in a first layout, and a second functional cell of the at least two non-identical functional cells includes second interconnection conductive patterns arranged connecting metal-zero structures corresponding to at least two metal-zero patterns in a second layout.