It is difficult for managers or other operators to decide how best to modify an available pool of resources used for their workflows. Methods for achieving this by improving the robustness of workflows are described. The more robust a workflow, the better its ability to withstand detrimental changes to its associated pool of resources. It is recognized here that the size of the solution space for the problem of allocating resources to tasks in a workflow provides a useful indicator of robustness of a workflow. In general, the greater the size of the solution space the more robust the workflow. A constraint optimization problem is specified for the problem of how best to modify resource characteristics of a pool of resources in order to maximize a size of a solution space. The solution space is that for the problem of allocating resources from the pool to tasks in a workflow.