Summary: Human resources have played an important role in the production systems of manufacturing enterprises. At the same time, human resource allocation, as a scheduling problem, has attracted more and more attention from the industry and academia, with the increasing complexity of technology and the rising cost of workforce. However, the existing scheduling methods fail to fully consider the relationship between tasks and employees. In this paper we consider a single workgroup scheduling problem with the assumption of human resources variability. Jobs must be assigned to employees, where the number of processing personnel and the processing time are variable for one job. We model the problem as a combinatorial optimization problem and the objective considered is to minimize the maximum finish time which is called makespan. This problem is transformed into a two-dimension rectangle strip packing problem and we propose a hybrid optimization algorithm which combines scheduling algorithm with packing algorithm. Finally, different size cases are adopted to test the model. Results show the proposed strategy and algorithm are suitable for solving single workgroup scheduling very well.