Page 180 - The Toyota Way Fieldbook

156 THE TOYOTA WAY FIELDBOOK

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8
A (ED) 250 250 250 250 250 250 250 250
B (ED) 220 220 220 220 220 220 220 220
C (ED) 210 210 210 210 210 210 210 210
D (EOD) 256 0 256 0 256 0 256 0
E (EOD) 250 250 250 250
F (EOD) 150 0 150 0 150 0 150 0
G (E4D) 0 240 0 0 0 240 0 0
H (E4D) 0 0 0 180 0 0 0 180
I (E4D) 180 0 0 0 180 0 0
J (E4D) 0 0 0 140 0 0 0 140
Other 0 225 0 325 0 225 0 325
Total 1,336 1,325 1,336 1,325 1,336 1,325 1,336 1,325
Goal 1,325 1,325 1,325 1,325 1,325 1,325 1,325 1,325
ED = every day; EOD = every other day; E4D = every four days.

Table 7-3. Alternative Leveled Production Pattern

repeating increment. In our case, the pattern has a four-day repeating sequence
and each item is leveled (the totals are equal) every four days. Toyota typical-
ly uses a monthly window for leveling, but it is based on a repeating multiple of
one day. Note: The main vehicle assembly line has a repeating pattern on a short
pitch frequency depending on the particular mix of vehicles produced, but the
supporting operations that are producing to a supermarket or “selectivity bank”
are producing to a different pattern that is a derivative of the primary pattern.
Notice that in the alternative pattern the total in days one, three, five, and
seven exceeds the daily goal. This is not a major problem since the amount is
within reasonable limits (normally a maximum of 10 percent). In most cases
when working with actual demands, the numbers don’t work out as evenly as
this example. For the first attempt, get the numbers as close as possible. After
you’ve had the opportunity to produce based on a level schedule, you will gain
a clearer understanding of the true need and will adjust the pattern accordingly.
It is much easier to calculate a leveled schedule than to actually produce
according to the plan! At first it’s likely that you will discover many obstacles that
prevent adherence to the schedule. These obstacles need to be systematically
identified and corrected so stability can be achieved (track causes for missing the
heijunka, and use the problem-solving method to eliminate them). The leveled
schedule should now be considered the “voice of the customer.” It is not the true