Modeling and simulation of production lines is considered to be important for designers who are
interested in: Work-load Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer
Allocation Problem (BAP). This paper studies and analyzes a real cement production line as a case
study. A simulation model is developed by ARENA software and used to analyze and test several
bottlenecks that are causing severe congestions in different areas on the production line and could
resolve all of these bottlenecks. Workstation failure data is collected along one year to obtain the
machines failure behaviors. This paper searches for the optimum buffer sizes with the increase of
the production rate. An actual cement production line is studied and analyzed by the simulation
model from stem to stern. After a simulation replication time of 12 days, a simulation results show
the line bottlenecks, workstations utilization, buffer capacities and the line production rate. To
resolve the bottlenecks, a redesign of allocation of buffers which verify an optimum size could be
made and it might be taken into consideration when designers implement this line. Finally modified
optimum workstations utilization, buffer capacities and the line production rate with an increase
about more than 15% of the production rate and economizing of 34 % of buffer capacities.