  BlueMUSE is an integral field spectrograph in an early development stage for
the ESO VLT. For our design of the data reduction software for this instrument,
we are first reviewing capabilities and issues of the pipeline of the existing
MUSE instrument. MUSE has been in operation at the VLT since 2014 and led to
discoveries published in more than 600 refereed scientific papers. While
BlueMUSE and MUSE have many common properties we briefly point out a few key
differences between both instruments. We outline a first version of the
flowchart for the science reduction, and discuss the necessary changes due to
the blue wavelength range covered by BlueMUSE. We also detail specific new
features, for example, how the pipeline and subsequent analysis will benefit
from improved handling of the data covariance, and a more integrated approach
to the line-spread function, as well as improvements regarding the wavelength
calibration which is of extra importance in the blue optical range. We finally
discuss how simulations of BlueMUSE datacubes are being implemented and how
they will be used to prepare the science of the instrument.
