Suppose there are three successive operations for a production process. Each operation is operated by a unique work center. Each work center can only process one unit simultaneously. The run time per unit for each operation (in minutes) is: Operation 1 2 3 Time 6 8 10 If the manager wants to increase the process capacity through process improvement, which operation should be focused on at first? Operation 1 Operation 2 Operation 3 All of the three operations equally