A resource allocation system begins with an ordered plan for matching requests to resources that is sorted by priority. The resource allocation system optimizes the plan by determining those requests in the plan that will fail if performed. The resource allocation system removes or defers the determined requests. In addition, when a request that is performed fails, the resource allocation system may remove requests that require similar resources from the plan. Moreover, when resources are released by a request, the resource allocation system may place the resources in a temporary holding area until the resource allocation returns to the top of the ordered plan so that lower priority requests that are lower in the plan do not take resources that are needed by waiting higher priority requests higher in the plan.