Lesson 4: Inherent simplicity and the current reality tree

Which system is more complex?

Picture two systems. System A has many separate parts, each doing its own thing, unconnected. System B has just as many parts, but they are tightly connected: every part affects others.

Most people say B is more complex: more connections, more to manage. TOC says the opposite. In A, every part needs separate attention: to control it, you must deal with each part. In B, because everything is connected, a few points govern the whole: touch the right one, and the rest moves with it. The more connected a system, the fewer the points that decide its performance. That is inherent simplicity, the first of TOC’s fundamental beliefs.

Faced with a messy situation, most managers take the System A approach: classify the problems, then search for a solution to each class. TOC looks for the connections instead.

“Every situation, no matter how complex it initially looks, is exceedingly simple.” — Dr. Eliyahu Goldratt

From many complaints to one root

A plant lists its problems: dissatisfied customers, late orders, constant expediting, high finished-goods stock, missing items in finished goods, high overtime, write-offs, unreliable vendors. Can you connect them?

This is a current reality tree (CRT). It answers TOC’s first question: what to change?

List the undesirable effects (UDEs): the symptoms people complain about, not causes.
Connect them with if-then logic: if this cause exists, then that effect follows.
Keep asking what causes each entry, until separate complaints trace back to a few root causes, often a single core problem.

A well-built tree usually shows eight to twelve UDEs converging on one or two causes. That convergence is inherent simplicity, showing itself in the logic. And very often, the core problem turns out to be a policy or a measure, not a physical limit.

Keeping the logic honest

A tree is only as good as its arrows. TOC gives everyone a depersonalised way to challenge an arrow, the categories of legitimate reservation. You aren’t saying “you’re wrong”; you’re saying “this connection needs checking.”

Clarity: is the statement clear enough to need no explanation?
Entity existence: does this really exist in this situation?
Causality existence: does this cause really produce this effect?
Cause insufficiency: is the cause enough on its own, or is something else also needed?
Additional cause: could another, independent cause produce the same effect?
Cause-effect reversal: is the arrow pointing the right way?
Predicted effect existence: if this cause were real, what else would we see? Is it there?
Tautology: is the reasoning circular?

Exercise: which reservation would you raise?

“Because the canteen food changed, delivery performance fell.”
“Because a machine broke down, the order was late.”
“Orders are late, so we must be short of capacity.”
“Because morale is low, the company is losing money.”

Check your understanding

Answer all five. Get four right to complete the lesson.

1. Inherent simplicity says that the more connected a system is…

The more points must be managed
The fewer the points that decide its performance
The harder it is to improve
The more data you need

Connections create leverage points.

2. The current reality tree answers which question?

How to cause the change?
What to change to?
Who is to blame?
What to change?

It finds the core problem behind the symptoms.

3. A current reality tree uses which kind of logic?

Sufficiency: if this, then that
Necessity: in order to, we must
Statistics
Opinion polls

Each arrow claims the cause is enough to produce the effect.

4. Challenging an arrow because “another, independent cause could produce the same effect” is…

Cause-effect reversal
Clarity
Additional cause
Tautology

Both causes may need different fixes.

5. Why use the categories of legitimate reservation?

To win arguments
To challenge the logic, not the person, so disagreement stays productive
To slow down meetings
To replace data

They depersonalise and depoliticise challenges.