Saudi Aramco operates a field located in a remote area in Saudi Arabia. The field is equipped with measurement, communication, control and software systems allowing real-time automated field management. It has the highest number of smart well completion installations in Saudi Aramco with 78 smart wells and 135 permanent downhole monitoring systems (PDHMS). The smart completion ensures controlled flow contribution from each targeted area within the reservoir, unlike open hole multilaterals where the inflow of oil from each lateral is uncontrolled.The productivity index (PI) of these smart wells is calculated based on the individual lateral productivity, which is quantified by measuring the lateral flow contributions at the surface testing facilities -multiphase flow meter (MPFM) or test trap. After the flowing period, the well is shut-in at surface allowing for pressure build up measurements. The same process is being carried out for the remaining laterals by operating the inflow control valves (ICVs).The assessment of the laterals productivity indices revealed a huge contrast between laterals of the same well. The stronger lateral dominates the flow, thereby not allowing flow contribution from other weaker laterals. This paper will demonstrate how proper utilization of ICVs combined with well testing enabled production optimization of the multilateral wells in the field. Production was restored from dead laterals by inducing only that lateral to the production system, laterals which were cutting water were restricted to gain overall production and less hydrostatic head pressure at the wellbore and laterals with high gas-oil ratio were restricted to gain total oil production from the multilateral well.