A future Demand Flexibility Service (DFS) must include a built-in mechanism to handle customer requests to switch between providers, an industry expert has urged. Naomi Baker, senior policy manager at Energy UK, chairs an industry working group which has recently outlined its views on how the DFS could be improved if it was deployed again next winter. A problem with the design of the DFS, Baker told Utility Week, is the fact there was no built-in mechanism to handle customers switching between providers.