Original Date: 07/14/1997
Revision Date: 01/18/2007
Best Practice : Material Tracking High Volume Line
In April 1996, Thermacore developed a disciplined process for tracking in-process work, scrap rates, and finished products on its high volume manufacturing lines. Prior to this, the company had no well-defined method for tracking defects or controlling manufacturing processes. Scrap rates were running at 25% to 30%.
Initially, Thermacore was a research and development company with low production volume. Demand for Thermacore’s products, from the computer industry, occurred within a short period of time, and then grew very rapidly from 2,500 units per month (June 1995) to 10,000 units per day (October 1996). The company had to develop a high yield, high volume, round-the-clock manufacturing capability to meet its customers’ requirements. Since heat pipes manufactured by Thermacore perform such a critical function, it is essential that 100% of the units shipped are defect free. Competitive pressures by foreign manufacturers also forced Thermacore to cut its high scrap rates in order to be cost competitive.
Many of Thermacore’s manufacturing processes require some decision making by production personnel. Therefore, the material tracking system needed to do more than just control the product from raw materials to a finished unit. The system needed to handle controlled quantities, evaluate performance throughout the manufacturing process, and track products back to individual processes. Above all, the tracking system had to ensure that Thermacore’s customers always receive defect-free products.
The new tracking system is designed to eliminate bottlenecks and identify problem areas. Raw materials are typically issued in lot quantities of 5,000 pieces. Each lot is broken down into smaller bin quantities of 600 pieces per bin. Bins are assigned a number and issued a material traveler. Manufacturing processes are broken into single operations. All operations have start, scrap, and finish quantities, as well as a completion date and operator initials. Each operation is entered into a computer database and tracked using bar codes and keyboard entries. Scrap quantities and scrap costs are calculated daily. All key management personnel are given a daily printout of the production quantities and scrap costs.
Thermacore’s tracking system has reduced the scrap rate from 30% to less than 1%. Problems can now be identified and quickly fixed. The tracking system can recognize many simple problems that were previously overlooked, but easily correctable. The system can also track problems to a root cause (e.g., operator, process, machine, tool). The improvement in yield has kept Thermacore’s products cost competitive on the world market.
Thermacore continues to improve its manufacturing processes and tracking system. Manufacturing processes are being automated to the maximum possible extent. Production personnel receive training whenever manufacturing processes are modified. Computers are playing an increasingly larger role in automating and controlling Thermacore’s processes. The company is incorporating log in/log out stations into its processing areas. All information will be entered by either touch screen input or bar code scanning, eliminating keyboard usage. This improvement will further reduce data entry errors. Thermacore has also purchased a quality assurance/data acquisition program which is currently being put on line. All Final Test operations are being added to this database. Eventually, all operations will feed this system via scanning devices and an RS485 data bus.
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