1. A system for evaluating a plurality of proposed solutions for a storage system that provides service to a plurality of workloads, the system comprising: a processor; and memory operatively coupled to the processor, the memory comprising a planner module configured for producing the plurality of proposed solutions, each proposed solution being associated with a final evaluation value, and ranking the plurality of proposed solutions based on the final evaluation value associated with each proposed solution, and an evaluation module configured for determining the final evaluation value for each proposed solution in the plurality of proposed solutions by determining a set of service level objective (SLO) evaluation values for a proposed solution, determining a set of cost evaluation values for the proposed solution, each cost evaluation value being based on a cost value of a cost metric, the cost value of a cost metric comprising a value for a type of hardware or software resource utilization of the storage system predicted to be incurred by executing the set of actions of the proposed solution, and producing a final evaluation value for the proposed solution by applying an evaluation function to the set of SLO evaluation values and the set of cost evaluation values, the evaluation function applying a set of cost weights to the set of cost evaluation values, each cost weight applied to a cost evaluation value determined for a cost metric, each cost weight comprising a weight value for the cost metric for increasing or decreasing an effect of the cost evaluation value, corresponding to the cost metric, on the final evaluation value.