2 Two main patterns are (i) Stuttgart in the January–March quarter is the more efficient plant. Frankfurt is the more efficient plant in the October–December quarter. Consider the ratio of Frankfurt Stuttgart for each manufacturing variable January–March April–June July–September October–December Manufacturing lead time 1.11 1.06 0.88 0.77 Total setup time for machines Total production time 1.09 1.03 0.94 0.83 Number of units requiring rework Total units started and completed 1.20 1.06 1.01 0.68 A rate greater than 1 indicates that Frankfurt is less efficient than Stuttgart. All three ratios in January–March (and in April–June, although to a lesser degree) show Frankfurt to be the less efficient plant. However, in the last quarter, Frankfurt is clearly the more efficient plant – it has a faster manufacturing lead time, a lower percentage setup time and a lower percentage of total units started and completed requiring rework. (ii) Frankfurt achieves major improvements in operating efficiency during 2007. Stuttgart’s performance is relatively static. Consider trends in each variable, where the value in January–March 2011 is scaled to be 100: January–March April–June July–September October–December Manufacturing lead time Frankfurt Stuttgart 100.0 100.0 94.6 98.8 80.4 101.2 67.4 97.6 Total setup time for machines Total production time Frankfurt Stuttgart
100.0 100.0
95.2 101.1
84.1 98.1
75.2 99.8 Number of units requiring rework Total units started and completed Frankfurt Stuttgart