p.11 The Theory of Constraints (TOC) is a prescriptive theory, which means it tells you not only
what's holding your system back, but also what to do about it and how to do it. A lot of theories answer the first
question - what's wrong. Some even tell you what to do about it, but those that do usually focus on processes rather than
the system as a whole. And they're completely oblivious to the concept of system constraints.
p.13 Systems thinking is preferable to analytical thinking in managing change and solving problems.
p.13 All systems operate in an environment of cause and effect. Something causes something
else to happen. This cause-and-effect phenomenon can be very complicated, especially in complex systems.
p.13 Identifying and eliminating a critical root cause not only eliminates all the undesirable effects that
issue from it, but also prevents them from returning.
p.22 In my strategy development work, I found the IO [Intermediate Objectives] Map to be not just
useful, but critical to success.
p.23 The Current Reality Tree (CRT) is a gap analysis tool... It helps us examine the cause-and-effect
logic behind our current situation and determines why that situation is different from the state we'd prefer to be in, as
expressed in the IO [Intermediate Objectives] Map.
The CRT begins with the undesirable effects we see around us - direct comparisons
between existing reality and the terminal outcomes expressed in the IO Map. It helps us work back to identify a few critical
root causes that originate all the undesirable effects we're experiencing. These critical root causes inevitably include 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.68, 69 An Intermediate Objectives (IO) Map is a graphical representation of a system's goal, critical
success factors (CSFs), and the necessary conditions (NC) for achieving them. These elements are arrayed in a logically connected
hierarchy, with the goal at the top, the CSFs immediately below it, and the supporting NCs below them. Each of the entities
in the IO Map exists in a necessity-based relationship (see Chapter 2) with the entities below it. The CSFs could be considered
major milestones, or terminal outcomes, on the journey to the goal. NCs represent the conclusion of significant activities
required to complete the CSFs.
Purpose
The IO Map is intended to fix in time and space a firm baseline or standard for what should be happening
if a system is to succeed. Its collective depiction of a goal, CSFs, and NCs constitute the system's benchmark of
desired performance - the destination toward which all system improvement efforts should be directed. In other words, before
you can decide how well you're doing, you must have a clear understanding of what you should be doing.
A well-constructed IO Map presents a rational, unemotional representation of the non-negotiable requirements a system
must satisfy in its quest to achieve its stated goal. These are not things you'd like to do, but
rather things you must do if the goal is to be achieved. Without such a frame of
reference, the determination of what should be changed within the system is merely a matter of opinion and speculation...By
now it should be clear that the Logical Thinking Process is a system-level problem-solving tool.
p.70 Span of Control
Simply put, our span of control includes all of those things in our system over which we have unilateral
change authority. In other words, we can decide to change those things on our own. Span of control varies for each
individual, but it has one common characteristic for everybody: it's extremely limited. It doesn't matter if you're the President
of the United States or a company employee - most of what you must deal with on a daily basis is beyond your unilateral control.
Sphere of Influence
Sphere of influence is an arbitrary perimeter enclosing those aspects of our lives that we can influence
to some degree, even if we can't exercise unilateral control over them. The sphere of influence obviously is substantially
larger than the span of control.
p.98 Keep the concepts of span of control and sphere of influence in mind while you're building
your Current Reality Tree, but don't let them limit you in its construction. Follow the cause-and-effect chain wherever
it may lead... Use it [sphere of influence] to help you decide for which problems you can reasonably expect effective results
and for which attack might be futile.
p.98 The power of the CRT comes from its basis in cause and effect. Sometimes people confuse
cause and effect with correlation. It's important to understand the difference between the two, because CRTs with correlations
embedded in them are likely to be invalid: They may isolate the wrong root causes, which could cost you time, energy, and
resources in trying to solve the wrong problem...
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 correlations 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.100 One of the first elements you will encounter in a Current Reality Tree is the undesirable effect,
or UDE (pronounced 'OOH-dee'). What is an undesirable effect? Essentially, it's the most prominent indication you
have that something might be amiss in a system. An UDE is something that really exists; something that is negative
compared with the system's goal, critical success factors, or necessary conditions... You might be aware of several UDEs.
Or you might just notice one. In a complex system, there will probably be several. But you can start a CRT with as few as
one.
p.102 We start with UDEs because doing so speeds our analysis of what's wrong with our system and
generally leads to faster improvement. UDEs are only the most visible results of much more complex interactions and
processes, but like a gopher hole in a perfectly manicured lawn, they're the "gateway" to finding the real underlying problem.
If you choose the wrong gateway, you won't find the right problem... In building a Current Reality Tree, we work our way from
UDEs back through the chain of cause and effect to root causes. The root cause is the beginning of the cause-effect relationship.
There may be several intermediate effects and causes between the root cause and the UDE... But when you've worked your way
down to a cause and you just can't go any farther, you're at a root cause... from a practical standpoint, you quickly exceed
your span of control and soon thereafter your sphere of influence. There's no point in working on something over which you
don't have at least some influence.
p.103 Every Current Reality Tree will have several root causes - maybe even a lot of them. 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 the few root causes that account for as many of
the system's UDEs as possible. Your purpose in building a Current Reality Tree is to try to find the very few root causes
that, if corrected, will have the greatest positive impact on system improvement - the most "bang for your buck."
p.105, 107 From its inception in the early 1990s, the Thinking Process was intended to find what Goldratt
referred to as a core problem - the one policy or practice that accounted for most of the undesirable effects experienced
by a system... we'll dig down to a few critical root causes that are both actionable and within the sphere of influence
of an accessible decision maker.
p.108 A critical root cause is a policy, practice, or prevalent behavior that constitutes the lowest level
of causality in existing reality lying within someone's sphere of influence to change.
p.110 With a Current Reality Tree... An entity is either a cause or an effect. Or it can be both - that
is, the effect of one cause and the cause of another effect. This is what enables us to create chains of cause and effect.
p.127-138 How to Construct a Current Reality Tree
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, or do you need to do some
research first? Are you able to recognize and understand patterns and interactions on your system?
- Do you care about finding a solution to the problem? Have you assumed ownership of the problem? Do
you have enough desire to fix it to justify the work that lies ahead?
If you can answer "yes" to these questions, you're ready to proceed... There's something you really need to
change about your circumstances. You are able to say, confidently, "My system really needs to improve in these areas..." ...
1. Define the System to be Modeled...
2. Determine the Undesirable Effects...
3. Determine the First Two Levels of Causality...
4. Begin the Current Reality Tree...
5. Improve the Logic of the Initial Clusters...
6. Identify Possible Additional Causes...
7. Look for Lateral Connections...
8. Build the Cause-and-Effect Chains Downward...
9. Scrutinize the Entire Current Reality Tree...
10. Decide Which Root Causes to Attack
