Page 74 - Lean six sigma demystified

Chapter 2 Lean Demy S tifie D 53

• reducing inventory
• encouraging continuous improvement.

A work cell contains three to nine people and workstations in a compact
U-shaped arrangement (Fig. 2-4). A cell ideally manufactures a range of highly
similar products. It should be self-contained with all necessary equipment and
resources. The U-shape makes communication easy because operators stay close
to each other. This improves quality and speed.

FIGURE 2-4 • Lean cell layout.

Most factory floors and even office floors are organized into functional cells.
Functional cells consist of similar equipment and activities. In a factory, a func-
tional cell might include a bank of lathes or presses or welders. In the offices of
old, there were groups of typists transcribing handwritten documents. In infor-

mation systems, there might be groups of system testers. In check processing,
there might be huge banks of check-sorting machines and clusters of people
balancing the amounts in each batch of checks. In medical imaging, X-rays, CT
scans, and MRIs form machine-based cells.
These functional cells do not serve to create a Lean environment. Some of
the problems include

• WIP often accumulates in front of these functional cells due to large batch
sizes.

• Transportation from one functional cell to another can be extensive.
• Functional cells use large, expensive equipment to gain economies of
scale.