Page 323 - The Handbook for Quality Management a Complete Guide to Operational Excellence

310 C o n t i n u o u s I m p r o v e m e n t A n a l y z e S t a g e 311

Excessive movement of material and/or personnel between process
steps is non–value added, as identified in the fourth definition of waste.
Efficient design of process layout reduces non–value added physical
movement. For example, a lab specimen moves from the process to a labo-
ratory, located on the other side of the plant. Once the specimen has been
analyzed, the results are forwarded to the quality department, then back
to the process where it is needed for the order to proceed.
A spaghetti diagram is useful to highlight the poor physical layout.
The 5S tools will be used in the Improve stage to create conditions for
reduced physical movement.
Waiting increases lead time by increasing both the completion time and
the number of items in queue. In that regard, its impact on the lead time
equation is magnified.
Process items will incur waiting when process personnel are unavail-
able to work on the process items. This can occur for a variety of reasons,
notably:
• Multitasking
• Process steps not balanced
• Long setup times

The case of multitasking within departments, or departments that are
specialized and receive process items from multiple sources, should be
identified. These issues can be addressed in the Improve stage through a
proper prioritization policy or dedicated personnel.
Level loading is used to balance, or match, the production rates of the
process steps. When we have achieved level loading of our processes,
then all work in progress (items in queue) are removed: there is no wait-
ing as items move from one process activity to the next. This reduction in
physical inventories improves cash flow and ultimately costs. The money
spent on partial or completed work generates no income to the organiza-
tion until the item is sold.
Inventories hide problems, such as unpredictable or low process
yields, equipment failure, or uneven production levels. When inventory
exists as work in progress, it prevents new orders’ being processed until
the WIP is completed. Although these concepts are most clearly identified
with manufacturing processes, they persist in service processes, where
inventory may refer to health care patients, hamburgers at the fast food,
or an unfinished swimming pool under construction.
Level-loaded flow is batchless, with a shorter cycle time per unit
(shorter lead time), increased flexibility, decreased response time, and an
increase in the percent of value-added activities.
To balance the process steps, we first calculate the takt time by divid-
ing the available resource (in units of time) by the production demand

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