1. A method comprising: under control of one or more processors configured with executable instructions: accessing objectives associated with execution of a workflow comprising a plurality of tasks that are combined to form the workflow; accessing information about a solution space, the solution space being for allocation of resources from a resource pool to tasks in the workflow in view of policy information; specifying a constraint optimization problem to find target resource characteristics for resources of the resource pool, the constraint optimization problem being specified such that the allocation of resources is based in part on assigning tasks to a worker that has not used a required skill set within a specified period of time; sending the specified constraint optimization problem to a constraint programming problem solver; receiving a response comprising target resource characteristics for resources of the resource pool; and storing the target resource characteristics in memory.