A member of the factory's planning and methods group took it upon himself to help the foreman reduce the high rejects on the small magnet line. After an analysis of the nature of the test rejects and at the completion of several process checks, the planner concluded that the defects were being caused by unsatisfactory furnace conditions during the sintering process.
The planner attempted, therefore, to adjust the furnace conditions so that satisfactory magnets could be produced continuously without an appreciable number of rejects. After several furnace changes, which seemed to have little success, he came to the conclusion that although the furnace might be the most important factor affecting magnetic quality, there were undoubtedly other contributing conditions, one or more of which had to be adjusted along with the furnace.