  Understanding the production of quarks and gluons in high energy collisions
and their evolution is a very active area of investigation. Monte carlo event
generator PYTHIA8 uses the parton shower model to simulate such collisions and
is optimized using experimental observations. Recent measurements of event
shape variables and differential jet cross-sections in pp collisions at
$\surd{s} = 13\, TeV$ at the Large Hadron Collider have been used to
investigate further the parton shower model as used in PYTHIA8.
