A shared computing infrastructure includes a plurality of computing engines, applications servers, and computing domains. A broker component executes a method for dynamically allocating the computing engines among the computing domains. The allocation method begins with the step of determining an expected number of computing engines to be allocated to each of the computing domains as a function of a predetermined service policy and a predicted demand for the domain While fewer than the expected number of computing engines has been allocated to each domain, the computing domains are sequentially selecting as a function of predetermined domain priorities. Unallocated computing engines are identified, and the unallocated computing engines are allocated to each selected computing domain according to predetermined selection rules for the domain. During an allocation improvement step, allocations among the computing domains are further adjusted to maximize a fitness statistic computed for the allocations.