An integrated approach to worker assignment, workforce flexibility acquisition, and task rotation

In a manufacturing environment, workforce flexibility can be achieved by cross-training and improved via job rotation. In firms with a flexible workforce, employees perform different tasks and functions in response to fluctuations in both product demands and labour resources. This paper presents a mathematical programming model that assigns workers to tasks, rotates workers between the tasks, and determines the training schedule. The objective is to minimize the total costs including training cost, flexibility cost, and productivity loss cost. A constructive-search heuristic is also developed to solve the proposed model. The algorithm provides good solutions in two phases: construction and improvement. At the construction phase, a solution is built using some problem-specific information. The quality of the solution is then enhanced by changing worker assignments at a particular time point during a planning horizon. Our computational results for a number of randomly generated test problems confirms the efficiently of the proposed method.