The process of zero-based budgeting removes the budget's baseline and requires every cost to be justified. In contrast to other budgeting techniques, it encourages critical thinking of historic expenses. It can offer big savings - but the process can also be complex, convoluted, costly and there are no guaranteed economies. Execution is key. In just-food's final part of our special report on zero-based budgeting, we look at best-practice on the implementation of the strategy.