Resource allocation, as an integral part of business process management (BPM), is more widely acknowledged by its importance for process-aware information systems. Despite the industrial need for efficient and effective resource allocation in BPM, few scientifically-grounded approaches exist to support these initiatives. In this paper, a new approach of resource allocation optimization is proposed, built on the concepts that is part of an operation-oriented view on process optimization. Essentially, the proposed approach automatically generates a specific task operation model (TOM) for a particular business process. In addition, in order to support end users in making sensible resource allocations, an ant colony optimization-based algorithm is presented, which makes it possible to search an optimal task operation path on the generated TOM. This allows one to suggest how a business user should efficiently allocate resources to perform the tasks of a particular process case. The feasibility of the presented approach is demonstrated by a simulation experiment. The experimental results show that the proposed approach outperforms reasonable heuristic approaches to satisfy process performance goals, and it is possible to improve the current state of BPM.