Implementation is likely to take place in a dynamic situation.  New policies and programmes might be introduced that bear upon the intervention and to which you can link.  Fresh evidence about what works with a target audience on a particular behavioural challenge may emerge that could influence the shape of your intervention.  Very often, things do not work exactly as planned with the intervention itself.

It is important to be alert to these and other possibilities as they can be helpful or disruptive. You will want to be in a position to make sure that the intervention team can take advantage of new opportunities that arise, and respond to possible problems, while at the same time keeping the intervention on course.