An article in Advanced Semiconductor Manufacturing Conference (ASMC) (May 2004, pp. 325–29) stated that dispatching rules and rework strategies are two major operational elements that impact productivity in a semiconductor fabrication plant (fab). A four-factor experiment was conducted to determine the effect of dispatching rule time (5 or 10 min), rework delay (0 or 15 min), fab temperature (60 or 80F), and rework levels (level 0 or level 1) on key fab performance measures.

The performance measure that was analyzed was the average cycle time. The experiment was blocked for the fab temperature. Data modified from the original study are shown in the following table.

(a) What effects are confounded with block? Do you find any concern with confounding in this design? If so, comment on it.

(b) Analyze the data and draw conclusions.

Transcribed Image Text:

Run Dispatching Rework Rule Time (min) Fab Average Delay Rework Temperature (min) Level (F) Cycle Time (min) I 5 0 0 60 218 23456 10 0 0 80 256.5 5 0 1 80 231 10 0 1 60 302.5 5 15 0 80 298.5 10 15 0 60 314 7 5 15 1 60 249 8 10 15 1 80 241