Systems and methods include an optimization-based load planning module for laboratory analyzers of bio-fluid samples. The optimization-based load planning module is executable on a computer server and is configured to optimize assay (lab test) assignments across a large number of laboratory analyzers based on one or more of the following user selected and weighted objectives: reduced turn-around-time, load balancing, efficient reagent usage, lower quality assurance costs, and/or improved system robustness. The optimization-based load planning module outputs a load plan comprising computer executable instructions configured to cause a system controller of a laboratory analyzer system to schedule and direct each requested test to be performed at one or more selected laboratory analyzers of the laboratory analyzer system in accordance with the user selected and weighted objectives. Other aspects are also described.