Customized Lean Case Studies

The customers of the CB Unit expect fast and on-time product deliveries, with high quality and at low cost. Reducing lead time (speed) and improving the service level (reliability) is thus of major importance.

In order to realize this, the CONWIP/FIFO/TAKT system has been developed. Three key lean principles were translated to the high-variety/low-volume situation of Eaton.

1.       CONWIP: a limit was set on the number of jobs in the CB unit. This measure takes care of short average throughput times of jobs.
2.       FIFO: the workers were stimulated to focus on the oldest jobs in the on-line scheduling of jobs on the work floor. This principle reduces the variability in throughput times of jobs.
3.       TAKT: the time principle was added to the system. The workers should be informed about their productivity: do they realize the manufacturing target of the day? 

The workers in the CB unit are responsible for having no more than a certain number of jobs in the system. The daily output of the CB unit, in terms of the number of jobs, indicates the number of jobs that may be released daily by the planning department. Released jobs are made visible in an input buffer. The first operation in the CB unit was punching. At this station, some nesting of jobs was important to save setup time. The puncher picks the best jobs from the input buffer A.

In order to support the workers in the CB unit, a screen is placed at the work floor that gives information about the Work-in-Process level, the FIFO-priority of jobs, and the extent to which the unit realizes the required TAKT-output.