With the information developed in Chapters 1 and 2, your next step is to utilize three tools to assess the efficiency of your existing layout and test proposed improvements.
Document the plant’s flow intensity
The From-To Chart summarizes the sequence and intensity of
material and component movements required to manufacture
the representative product mix. Its objective is to highlight
the pairs of Process Elements with the heaviest flows.
To populate the chart the component volumes that move
from Element to Element must be estimated. Using the
Process Sequence Charts developed in Chapter 1 you can
extrapolate the component sequences for each product and
quantify the flows by multiplying the quantity per period of
each product by the individual component requirements.
Next you must convert each component’s volume into the
number of cart or pallet loads that must be moved through
the plant during the period. Figure 1 shows a simple table
that estimates the number of loads for each process sequence.
Elements in each process sequence are referred to by numbers rather than names such as Panel Mill, Finishing, etc.
Figure 1 tells you that 4,000 Tops per month requires 20 loads
each consisting of 200 individual tops. Those 20 loads move
from Process Element 1 to Process Element 2 then to Process
Element 4 and so on until completed at Process Element 8.
To construct the From-To Chart shown in Figure 2:
1. Create a matrix for each product listing the name of the
plant’s Elements in identical order across the top of columns
and down the rows on the left side of the matrix. Note: if the
lists follow the general flow in your plant, entries below the
diagonal line show backtracking required by existing layout.
1. Note the number of loads in the cell for each pair of
Elements in a component’s sequence and total the loads once
all components for a product are entered. For example the
cell for movements from Element 4 to 5 consists of 20 loads of
Tops plus 5 loads of Doors for a total of 25 loads.
2. Complete a From-To Chart for each family of products
in your representative mix. Don’t forget to map the movement
of waste, rework, empty carts, and supplies.
3. Check for accuracy by summing the row and column
sub-totals to the lower right hand cell.
Estimate handling cost
To achieve the optimal arrangement of a plant’s Elements,
you must consider the cost of handling. Using the distance
between Elements as a proxy for handling cost, the Travel
Chart computes the total distance that loads of materials and
by Art Raymond
email@example.com RAYMOND’S VIEW
Chapter 3 -- Rationalizing your plant layout
Evaluating your current layout and identifying improvement opportunities.