  Aims: In this paper we study whether the shock-in-jet model, widely used to
explain the outbursting behaviour of quasars, can be used to explain the radio
flaring behaviour of the microquasar Cygnus X-3.
  Method: We have used a method developed to model the synchrotron outbursts of
quasar jets, which decomposes multifrequency lightcurves into a series of
outbursts. The method is based on the Marscher & Gear (1985) shock model, but
we have implemented the modifications to the model suggested by Bjornsson &
Aslaksen (2000), which make the flux density increase in the initial phase less
abrupt. We study the average outburst evolution as well as specific
characteristics of individual outbursts and physical jet properties of Cyg X-3.
  Results: We find that the lightcurves of the February-March 1994 and
September 2001 outbursts can be described with the modified shock model. The
average evolution shows that instead of the expected synchrotron plateau, the
flux density is still increasing during the synchrotron stage. We also find
that high frequency peaking outbursts are shorter in duration than the ones
peaking at lower frequencies. Finally, we show that the method can be used,
complementary to radio interferometric jet imaging, for deriving the physical
parameters such as the magnetic field strength and the energy density of
relativistic electrons in the jet of Cyg X-3.
