Accepting that increased climate variability will require that farmers make significant changes to their farm systems, we can see that maintaining flexibility is an important coping strategy. Using general systems theory, we offer a conceptual model for describing the tactical and strategic flexibility of farm systems to reveal the sensitivity of farm systems to variable critical inputs. The model is used to classify farm systems as rigid, robust, or elastic on the basis of two factors, the capacity of the farmer to reduce reliance on critical inputs by altering the following: (i) the use of critical inputs and (ii) farm output. The different production emphasis for the different types of systems has implications for how these farmers are able to respond to increased variability and on public policies that may support viable farm businesses in the face of increased variability. Copyright © 2012 John Wiley & Sons, Ltd.