  Experimental measurements of observables sensitive to the underlying event
(UE) in $Z$-boson events have been performed by both ATLAS and CMS experiments
at the LHC. However, in the busy LHC environment, these observables receive
substantial contribution from jets originating from initial state radiation
(ISR). We probe if using event shape observables in conjunction with the UE
observables can help us to disentangle the effect of the UE from jets
originating in ISR.
