| Work
balance within a manufacturing cell or work cell is a primary
determinant of the cell's efficiency and one of
several design issues. Work balance is a lot more involved than
most people recognize. This page introduces the topic and the
downloadable paper addresses these issues in considerable
detail.
Production
Line Balance
Henry
Ford's highly balanced assembly line has been the dominant
production model for almost 80 years. But such lines have
significant problems. Most short-cycle
lines that appear to be balanced actually have significant
balance losses that exceed 20%.
The
Effects of Imbalance
Imbalance
can produce several negative effects. Among these effects are:
-
Excess
Inventory
-
Idle
Equipment
-
Idle
People
-
Team
Dissension
-
Individual
Frustration
Static
and Dynamic Balance
Production
lines can have perfect average or static balance and yet be
highly unbalanced from cycle-to-cycle (dynamic balance).
Understanding these factors is important when selecting balance
methods.
People
and Equipment
In
Cellular Manufacturing it is
important to divorce people from machines or workstations.
This is often a difficult paradigm shift but it is necessary for
three reasons:
1.
The time required for a person at a given workstation may differ
from the machine time.
2.
The workstations in a work cell or production line rarely have
perfect balance and therefore most workstations have idle
periods.
3.
People are more flexible than machines
and can utilize balance methods that are unavailable for
equipment. |
Circulation
or Chaku-Chaku
Equipment
Balance Methods
Balancing
equipment is often unnecessary or even counterproductive.
There are important advantages from excess equipment capacity in
a work cell. The following methods are available for equipment
balance:
-
Inherent
Balance
-
Queuing
-
Surplus
Capacity
People
Balance Methods
Balancing
the work of people in a cell is critical. An idle person costs
more than most idle machines. In
addition, people perceive a work imbalance as unfair
and this causes frustration and dissension in the
work cell
team. Here are the methods available for balancing people:
-
Inherent
Balance
-
Queuing
-
Surplus
Capacity
-
Floating
Balance
-
Circulation
Download
The Complete Paper
The
link below allows you to download the complete paper, originally
delivered at the 2000 IIE conference. There you will find
detailed information, illustrations and examples.
______________________
LEE,
QUARTERMAN, "How to Balance work cells", Institute of
Industrial Engineers, Proceedings, May 21-23, 2000 |
