Borel-Ecalle resummation is a vast generalisation of a the Borel-Laplace
resummation theory. Using resurgent function and the notion of
well-behaved average it allows to resum some divergent series in a
direction where its Borel transform has singularities. I will spent time
presenting this method before applying to the two-point function of a
QFT. Namely, I study the Schwinger-Dyson equation and the
renormalisation group equation of the Wess-Zumino model, and show that
their solution is Borel-Ecalle summable.