Page 251 - How To Implement Lean Manufacturing

The Story of the Bravo Line 229

After Leaning Out
Other Impacts Original Case the Process % Reduction
Space Impacts 8 line-days per Less than 5 line-days per ~70%
week, plus 600 week, with less than 100
sq. ft. of buffer sq. ft. of buffer inventory
inventory
Manpower 14-person line 9-person line running 60%
Impacts running 3 shifts 3 shifts for 5 days per
for 8 days per week = 135 md/10,000
week = 336 md/ units
10,000 units

TABLE 15-2 Other Benefits
• By implementing jidoka as we did, using line shutdowns, we literally equated
quality with production. If quality was bad, production went to zero until
quality was reestablished as good. This is the beginning of a huge cultural
change from an attitude of “production trumps all” to an attitude of “we will
only allow the production of product that is satisfactory to our customer.”
• Overall lead time is a very important metric. It is the sign of both flexibility and
responsiveness. The reduction of overall lead time is basically done by reducing
lot wait times and process delays, or “queue time” as some call it. In this case,
process delays, due to the imbalance situation also contributed greatly to the
overall lead time.
• By converting to one-piece flow (actually two in this case), we allowed the
quality problems to be found and solved. Finding and eliminating quality
problems are not basic Lean elements. Finding and eliminating quality problems
is not quantity control, it is quality control. It is a precursor to Lean. This allowed
us to reduce the manpower needs from 336 md to 210 md per 10,000 units. That
is a huge savings, or better yet a huge loss reduction. (See Table 15.2 earlier:
210 md is calculated by 14 persons, over five days for three shifts to produce the
10,000 units—in other words, their planned staffing.)
• The second reduction, from 210 md to 135 md per 10,000 units came about by
balancing line production to takt. This is not a new Lean technique. It is an age-
old industrial engineering tool known to every manufacturing firm that has
significant labor costs.
• After the line was balanced and flowing, it improved itself! Recall that
production rates increased even after we had completed our changes.

In Summary
• The company was now able to produce to schedule, and missed shipments
dropped to zero.
• First piece lead time was reduced from 3.9 hours to 6.5 minutes.
• They had now reduced the lot lead time from over six days to less than
30 hours.