xxi W. Edwards Deming [http://en.wikipedia.org/wiki/W._Edwards_Deming] maintained that real quality improvement isn't possible without profound knowledge. According
to Deming, profound knowledge comes from an understanding of the theory of knowledge, knowledge of variation, an understanding
of psychology, and an appreciation for systems.
Most modern organizational systems are considered to be cybernetic systems. that is,
they are capable of self-adjustment... cybernetic systems can redesignate their goals, too, in response to changes
in their environment. So, if we appreciate a system, it would mean that we thoroughly understand how the system interacts
with its environment. Such understanding is indispensable to effective change.
Eliyahu M. Goldratt's Theory of Constraints is a system improvement philosophy.
xxi-xxii Goldratt, however, maintains that organizations live or die as systems, not as processes. Their
success or failure is a function of how well the different component processes interact with each other... Goldratt's Theory
of Constraints is the paradigm he's created to manage the living daylights out of these weakest links, with the end result
that systems improve much more quickly than they might otherwise... The Theory of Constraints (TOC) is really a collection
of system principles and tools, or methods for solving the problem of improving overall system performance... TOC
can be used to completely reengineer a business or organization as well... The content of this book constitutes
my understanding and interpretation of the TOC Thinking Process, and I've endeavored to describe and apply it as faithfully
as possible... certain elements of this book diverge somewhat from Goldratt's teachings. Almost without exception, these "departures"
result from my continuing efforts to make the complexities of the thinking process easier for people to understand and quicker
to learn.
p.4 quality (or lack of it) doesn't exist in a vacuum. It can only be considered
in the context of the system in which it resides. So, to follow Deming's line of reasoning, it's not possible
to improve quality without a thorough understanding of how that system works.
p.4-5 The essence of management is recognizing the need for change, then initiating, controlling, and directing
it, and solving the problems along the way... In a general sense, the Theory of Constraints is about management.
p.5 One of the hallmarks of effective managers is that they deal less with the present and more with the
future.
p.5 "It is more important to know where you are going than to get there quickly. Do not mistake
activity for achievement." - Mabel Newcomber
p.5 No manager can hope to succeed without knowing three things:
- What the ultimate goal is
- Where he or she currently stands in relation to that goal
- The magnitude and direction of the change needed to move from the status quo to where he or she wants to
be (the goal)
p.6-7 A goal can be defined as the result or achievement toward which effort is directed. A necessary
condition is a circumstance indispensable to some result, or that upon which everything else is contingent... Are
you attaining that goal right now? If not, could you be doing better? Most people would agree that they
could be doing a better job of progressing toward their goal. Okay, what keeps your system from doing better? Would
it be fair to say that something is constraining your system - keeping it from realizing its maximum potential? If
so, what do you think that constraining factor might be? ...If you can successfully answer that question, you probably
have a bright future ahead of you.
p.11 Goldratt's Theory of Constraints is essentially about change...
- What to change? (Where is the constraint?)
- What to change to? (What should we do with the constraint?)
- How to cause the change? (How do we implement the change?)
Remember that these are system-level, not process-level questions. The answers to these questions
undoubtedly have an impact on individual processes, but they're designed to focus efforts in system improvement. Processes
are important, but our organizations ultimately succeed or fail as systems.
p.12 Systems thinking is preferable to analytical thinking in managing change and solving problems.
p.13 An optimal solution deteriorates over time, as the system's environment changes.
p.15 "Elevating" the constraint means that we take whatever action is required to eliminate the constraint.
When this step is completed the constraint is broken.
p.15 A burning question we have to address is, "How do we know whether our constraint-breaking has had a positive
effect on our overall system?"... Part of the answer to the question lies in the TOC emphasis on fixing the weakest link (constraint)
and ignoring, at least temporarily, the nonconstraints... By doing essentially the same thing in our organizations
(that is, working only on the constraint), we achieve two benefits: (1) we realize the maximum system
improvement from the least investment in resources, and (2) we learn exactly how much effect improving a specific system component
has on overall system performance.
p.21 The Theory of Constraints is considerably more than just a theory. In effect, it's a paradigm, a pattern
or model that includes not only its concepts, guiding principles, and prescriptions, but its tools and applications as well.
p.21 Each application of TOC starts out being unique. As the theory is applied in a new situation,
it creates a distinctive solution. Often, however, such solutions are easily transferable to other circumstances.
p.22 The Current Reality Tree (CRT) is a problem-analysis tool... It helps us examine the cause-and-effect
logic behind our current situation. The CRT begins with the undesirable effects we see around us and helps us work
back to identify a few root causes, or a single core problem, that originate all the undesirable effects we're experiencing.
The core problem is usually the constraint we're trying to identify in the Five Focusing Steps. The CRT
tells us what to change - the one simplest change to make that will have the greatest positive effect on our system.
p.23 The Future Reality Tree (FRT) serves two purposes... First, it allows us to
verify that an action we'd like to take will, in fact, produce the ultimate results we desire. Second, it enables us to identify
any unfavorable new consequences our contemplated action might have, and to nip them in the bud.
p.45 complex causality is a situation in which a given effect might have more than one cause... Basically,
if you want to get rid of the effect, you have to eliminate all the causes. Removing only one or two might not do any good,
because any remaining cause can still produce the effect by itself.
p.66 The objective of the Current Reality Tree is to help you isolate what needs changing in any situation.
It does this by helping you identify the things you aren't currently satisfied with and by tracing those "gripes" back to
one or more basic causes.
p.66 Because most situations are complex, often with inconspicuous causes driving the results,
it can be difficult deciding what to change to make the situation right. A Current Reality Tree can
help reveal complex relationships.
p.67-68 We all function in complex systems with varying degrees of control over our environment.
In some areas we have a high degree of control over parts or functions of that environment. These areas are said to lie within
our span of control. We enjoy virtually complete authority to change anything within our span of
control. Just outside our span of control lies our sphere of influence, a region of the environment
where we can influence things to varying degrees but don't enjoy direct control. Beyond our sphere of influence we
have neither control nor influence
p.68 Keep this concept of span of control and sphere of influence in mind while you're building your
Current Reality Tree. Don't let it limit you in its construction: Follow the cause-and-effect chain wherever it may
lead you. But after the tree is done, and before you select which problem to attack, revisit the issue of sphere of influence.
Use it help you decide which problems you can reasonably expect effective results on and which ones might be futile to attack.
Generally, solving problems, especially big ones, is a game in which you try to see how far toward the outer limits
you can stretch your sphere of influence.
p.69-70 The power of the Current Reality Tree comes from its basis in cause and effect. Sometimes
people confuse cause and effect with correlation...The difference between correlation and cause and effect is essentially
the difference between how and why. Without knowing why, you'll never know what makes the correlation exist.
This means you'll never be sure whether the correlation depends on other variables you haven't identified. In a problem analysis
situation, this could cause you to focus on the wrong problem. It also means that you won't be able to effectively predict
future instances of the correlation, because you'll never know whether a key variable is present or not.
p.71, 73 One of the first elements of a Current Reality Tree that you will encounter is the undesirable
effect (UDE). What is an undesirable effect? Essentially, it's the first indication you have that something might be amiss
in a system. A UDE is something that really exists and is negative on its own merits... We start
with UDEs because doing so speeds our analysis of what's wrong with our system and generally leads to faster improvement.
The UDEs are only the most visible results of much more complex interactions and processes, but they're the "gateway"
to finding the real problem.
p.74-75 One root cause in any Current Reality Tree is likely to be the origin of a substantial number
of UDEs... The primary objective of the CRT is to work backward from UDEs through a chain of cause and effect to
identify this root cause. When this cause accounts for 70 percent or more of the UDEs in a CRT, it is considered a core
problem (CP).
p.75-76-77 While every Current Reality Tree can be built downward to a core problem eventually, that
core problem may be beyond your sphere of influence... if you don't have much chance of affecting the core problem,
you'll have to deal with the root causes you can influence... your purpose in building a Current Reality
Tree is to try to find the one problem that, if corrected, will have the greatest positive impact on system improvement -
the most "bang for your buck."
p.80 With a Current Reality Tree, the issue is simple: An entity is either a cause or an effect. Or it can
be both
p.88-98 Now you're ready to begin constructing your own Current Reality Tree. Before you start, does your
situation qualify for a CRT?
- Do you have adequate intuitive knowledge about the situation? Are you able to recognize
and understand patterns and interactions in your system?
- Do you care about finding a solution to the problem? Have you assumed ownership
of the problem? Do you have a burning desire to fix it?
If you can answer "yes" to these questions, you're ready to proceed... What's the first thing you must do?
1. Identify Your Span of Control and Sphere of Influence...
2. Create a List of Undesirable Effects...
3. Begin the Current Reality Tree...
4. Connect the First Two UDEs...
5. Connect Other UDEs...
6. Build the Cause-and-Effect Chain Downward...
7. Redesignate UDEs...
8. Identify Root Causes and the Core Problem...
9. Look for V-Shaped of Missing Connections...
10. Decide Which Root Causes to Attack
p.97 the TOC thinking process is a minimalist approach: it helps you to solve the
problem with the least investment in time and resources that will do the job effectively. By working down to the core
problem, which is really the system's constraint, you identify the one thing to change that will do the most good
- that will achieve the most "bang for your buck."
p.357-358 Constraint. [definition] Any element of
a system or its environment that limits the output of the system. Analogous to the weak link in a chain.
The entity that will ultimately prevent increases in Throughput regardless of improvements made to any other part
of the system. May be physical (equipment, facilities, and so forth) or policy. If the capability of the system is
not constrained internally (such as by physical means or policy), the constraint may lie outside the system, in the environment
(for example, market demand).
