Goldratt’s TOCThinking Process

Using the TOC Thinking Process to Identify Problems, Develop Alternatives,

and Implement Solutions

Ed D. Walker II

Department of Management

Langdale College of Business Administration

Valdosta State University

Tools created by Eli Goldratt

• What to change?– Current Reality Tree

• To what to change?– Evaporating Cloud– Future Reality Tree & Negative Branch

• How to change?– Prerequisite Tree– Transition Tree

The Future Reality Tree & Negative Branch Reservation

• Today we will focus on the second question

• To What to Change?

We Have an Injection from the Evaporating Cloud.

Now What?• We must check to see whether the

injection(s) remove(s) all of the UDEs in our CRT.

• Additionally we must be sure that the injection doesn’t cause any UDEs when implemented.

Definitions - FRT• Future Reality Tree -- a logic-based tool for constructing and testing potential

solutions before implementation. The objectives are to (1) develop, expand, and complete the solution, and (2) identify and solve or prevent new problems created by implementing the solution (APICS Dictionary, p. 35.)

Desirable Effect Desirable

Effect

Desirable Effect

Desirable Effect

Injection

Injection

Injection

This thinking processenables a person toconstruct a solutionwhich, when implemented,replaces the existingundesirable effectswith desirable effects.

Definition -- NBR• Negative Branch Reservation -- a logic- based tool using cause-and-effect

relationships to identify the possible negative effects created by the implementation of the solution.

UndesirableEffect

DesirableEffect

Injection

UndesirableEffects

UndesirableEffects

DesirableEffect

This thinking process enablesa person to clearly indentifythe possible undesirable effects of implementing a proposed solution.

Purpose of the FRT

• Enables effectiveness testing of new ideas BEFORE committing resources to implementation.

• Determines whether the proposed changes will have unintended consequences.

• Serves as the initial planning tool for changing the course of the future.

Assumptions of the FRT• System components are interdependent. A

change in one affects others.

• Change has both intended and unintended effects.

• Unintended effects can be anticipated.

• Some changes cause more problems than they solve.

• Ideas do not become solutions until they have been validated.

FRT in a Nutshell

• The FRT is used to test possible solutions BEFORE implementation.

• The desired outcome is to turn the original UDEs from the CRT into their opposites, (Desirable Effects)

• Additionally, the NBR exposes weaknesses in the solution.

Simple Example of FRT

Successful powered flight is achieved.

Bernoulli's Principle applies.

Wright brothers create a way to

sustain air flow over a wing.

Element of existing reality. Injection

Expected Outcome

Simple Example of NBR

Enact the Immgration

Reform Act of 1986.

Desired Effect:End illegal entry

into the U.S.

Employers must verify

legal residencey.

Money can be made by selling

false documentation.

Illegal immigrants don't

have proof of residency.

Underground industry in forged

documents develops.

A complex Solution may require several Injections

Injection #1 Reality Reality Injection #2

Expected Reaction

Expected Reaction

Expected Reaction

Injection #3

Desired Effect

Another NBR

My children need to get to school.

You offer to do me a favor

You drive my children to

school.

INJECTION:I lend you my car.

You've had four accidents in the last six months.

You wreck my car.

Undesirable predicted effect.

Desired outcome

Trimming the NBRRequires another injection

My children need to get to school.

You offer to do me a favor

You drive my children to

school.

INJECTION:I lend you my car.

You've had four accidents in the last six months.

My car is safe. Desired outcome

INJECTION #2You agree to let your wife

(who has never had an

accident) drive my car.

Desired outcome

Building the FRT• Gather all of the information and materials.

• Formulate the desired effects.– Positive, not neutral– Use present tense– Lay out Desired Effects

• Add the injection(s) at the bottom.

• Fill in the gaps (building upward)

• Add additional injections as necessary.

• Build reinforcing loops if possible.

• Look for and trim NBRs