Page 185 - The Toyota Way Fieldbook

Chapter 7. Leveling: Be More Like the Tortoise Than the Hare 161

Quantity
Patterns per Hourly Containers
Part Name Ratio per
Hour Requirement per Pitch
Container
A 4 6.25 4 6.25 25 10 2.5

B 2 6.25 2 6.25 12.5 5 2.5
C 1 6.25 1 6.25 6.25 5 1.25
D 1 6.25 1 6.25 6.25 5 1.25

Table 7-5. Calculation of Containers Moved per Pitch

Let’s also assume that we want the material handler to move material every
hour (the pitch for material replenishment). Table 7-5 shows the calculation of the
number of containers that will be moved during each one-hour material replen-
ishment cycle.
Based on the material movement requirement during a one-hour cycle time,
it is possible to define standardized work, including the specific route of travel and
other processes that will be serviced during the route.

Slice and Dice When Product Variety Is High

Heijunka seems straightforward enough when you are dealing with 5 to 10
products. But what happens when there are many different finished products?
One company claimed to have 25,000 individual finished goods part numbers
and insisted heijunka was impossible. How would it be possible to level with
this kind of variety? We have to go through a process we call “slice and dice,”
which is a method of dividing the whole into groups of products with similar
characteristics (you may also think of this as “divide and conquer”).
The first “slice” separates products into value streams that have common
products and processing steps. This grouping puts like items together and also
reduces the overall number of items within the slice—the 25,000 may now only
be 5,000. Think of your operation with the variety of products and processes in its
entirety as a rectangle. The separation into value stream “families” with common
characteristics and processing steps would divide the rectangle horizontally
into slices (Figure 7-3). If the most important value stream overall is addressed
first, the greatest benefit will be achieved from the effort.
If the slice is “diced” (Figure 7-4), the most significant items within the 5,000
are isolated, and the primary focus is reduced further. The “dicing” of the value