Production: There are 85 employees in the production unit, including one production manager, four engineers and 80 operators who mainly work with machines. There are some bottlenecks in the production lines, which caused delays in the production line and miss achievement in targeted goals that increased the production to 30%. The production engineers believe that this is happening because of the variation in operators' performance. Some operators work fast and some work slow, because they are paid based on their working hours, not the number of pieces. The production manager does not accept this idea and thinks that the difference in the operation period in different stations is the cause of bottlenecks. Table 7 indicates the minimum time required for operation by an operator in each station in production line A, the real-time consumed for operation in each station and the number of workers in each station who do the same work. Table 7. details of production time in line A Stations 1 2 3 4 5 6 7 8 Total Real consumed time in each station 60 180 100 60 180 90 85 90 120 90 60 80 Standard required time for an operation 60 120 100 120 in each statement with one operator Number of operators in each station 1 2 2 2 Bottlenecks 2 1 1 2 2 B What is the problem? The operator's performance or production line design caused a bottleneck? What should be done for decreasing bottlenecks and reaching to a production target