Monte Carlo Generators for the Production of a $W$ or $Z/\gamma^*$ Boson in Association with Jets at ATLAS in Run 2

This note documents the Monte Carlo generators used by the ATLAS collaboration at the start of Run 2 for processes where a $W$ or $Z/\gamma^*$ boson is produced in association with jets. The available event generators are briefly described and comparisons are made with ATLAS measurements of $W$ or $Z/\gamma^*$+jets performed with Run 1 data, collected at the centre-of-mass energy of 7 TeV. The model predictions are then compared at the Run 2 centre-of-mass energy of 13~TeV. A comparison is also made with an early Run 2 ATLAS $Z/\gamma^*$+jets data measurement. Investigations into tuning the parameters of the models and evaluating systematic uncertainties on the Monte Carlo predictions are also presented.