Work-force management in automated assembly systems

While issues like off-line short-term scheduling, sequencing, real-time control and rescheduling of automated manufacturing or assembly systems are well established and widely discussed in literature, human resources have seldom been considered a critical management parameter in the addressed industrial contexts, since they are characterized by a high level of automation. The objective of this study is the assessment of the influence of work force and related management policies on the operating performances of an automated assembly system. Although workers' main tasks, in these systems, are characterized by short duration and tend to be spaced by long intervals, during which automated machines operate autonomously, it is postulated that the way the human interventions on the system are organized may have a profound impact on its performance. For this purpose, a simulation model of a real automated printed circuit board assembly system has been used to test the comparative effectiveness and efficiency of different work-force management rules. More in detail, we compared several work-force management contexts differing in the number of workers in the crew, the way tasks are assigned to operators and the way operators are assigned to machines in the shop. The obtained results allowed us to disclose useful directions on work-force management in automated systems, highlighting how job enlargement issues, typical of lean production philosophy, have great relevance in determining the best work-force management policies.