The design of a job or process has an impact on human behavior and thus on production performance. Incorect job design may lead to absenteeism and turnover. Absenteeism causes fluctuations in production and turnover may slow it down. Correct job design decreases the sensitivity of the technical system to the human one; if instead of a single line, two parallel lines are used, the production system is less sensitive to absenteeism, since the absence of a person disturbs only one half of the system. This paper develops a simulation model to examine the influence of various job design strategies (number of parallel lines) on human behavior (learning, absenteeism, turnover) and the system's response time and percent of work accomplished. The model has been tuned to a specific process and results demonstrate that in certain cases a compromise strategy which consists of a few parallel lines is better than each one of the extreme strategies, where a single line of n stations or n parallel lines of one station are used.