Page 91 - The Handbook for Quality Management a Complete Guide to Operational Excellence

78 I n t e g r a t e d P l a n n i n g S t r a t e g i c P l a n n i n g 79

independent chains in a par ticular system—whether a manufacturing,
service, or government system—at any given time, only a very few vari-
ables truly determine the performance of the system.
This idea has profound implications for managers. If only a very few
vari ables determine system performance, the complexity of managers’
jobs can be dramatically reduced. Look at it in terms of the Pareto rule,
which suggests that only 20 percent of a system accounts for 80 percent of
the problems with in it. If this is a valid conclusion, managers should be
able to concentrate most of their attention on that critical 20 percent.
Goldratt’s concept of chains and “weakest links” takes the Pareto concept
a step further: the weakest link accounts for 99 percent of the success or
failure of a system to progress toward its goal (Goldratt, 1990, p. 53).

Basic Constraint Management Principles and Concepts
Constraint management exhibits the theoretical foundation that Deming
considered so important to effective management action (Deming, 1986).
Theories can be either descriptive or prescriptive. A descriptive theory
general ly tells only why things are the way they are. It doesn’t provide
any guidance for what to do about the information it provides. An example
of descriptive theory might be Newton’s laws of gravitation, or Einstein’s
theories of relativ ity. Prescriptive theory describes, too, but it also guides
through prescribed actions. Most management theories are prescriptive.
The Deming philosophy prescribes through its 14 points (Deming, 1986).
Ken Blanchard’s One-Minute Manager (Blanchard, 1982) and Peter Senge’s
The Fifth Discipline (Senge, 1990) explain prescriptive theories in detail.
Constraint management is prescriptive as well. It provides a common
definition of a constraint, four basic underlying assumptions, and five
focusing steps to guide management action.

Definition of a Constraint
Simply put, a constraint is anything that limits a system (company or agency)
in reaching its goal (Goldratt, 1990, pp. 56–57). This is a very broad defini-
tion, because it encompasses a wide variety of possible constraining ele-
ments. Constraints could be physical (equipment, facilities, material,
people), or they could be policies (laws, regulations, or the way we choose
to do business—or choose not to do business). Frequently, policies cause
physical constraints to appear.

Types of Constraints
Identifying and breaking constraints becomes a little easier if there is an
orderly way of classifying them. From the preceding discussion, we know
that system constraints can be considered either physical or policy. Within
those two broad categories, there are seven basic types (Schragenheim
and Dettmer, 2000, Chap. 4):

05_Pyzdek_Ch05_p061-102.indd 78 11/9/12 5:04 PM