The Future Reality Tree (FRT) Notation
Estimated reading time: 2 minutes.
Why use Future Reality Trees (FRTs)?
FRTs lay out a sequence of cause-and-effect relationships that connect proposed solutions to desired effects (DEs). FRTs use 'If... Then...' logic to answer the question, 'TO WHAT should we change?'
In contrast with a Current Reality Tree (CRT):
- A CRT starts with a set of Undesirable Effects (UDEs), leading down to the Core Driver, from which we invent Solutions.
- An FRT begins with a potential Solution and builds upward to a set of Desirable Effects (DEs).
FRTs can be constructed not only from a previously conceived solution but also from other parts of previously created CRTs and Clouds.
FRT Notation Description
The diagram below outlines the notation's structure. CRTs start by listing the known Undesirable Effects (UDEs) in a particular area. It's suggested to gather between 5 and 10, but there's no strict limit.
From there, we follow sufficient cause logic to identify the causes. Each cause itself is an effect (desirable, undesirable, or intermediate). There are two more "causes" typically located at the bottom of the diagram. These causes are "Given" (things that you cannot change) or "Changeable" (things that you could change). Changeable causes are the most interesting ones since changing what you can alter is the easiest path to improvement.
The Node Types in detail:
| Node Type | Description | Is Starting Point | Successors |
|---|---|---|---|
| Undesirable Effect | Undesirable Effects (UDEs) are the starting points for current reality trees. List them first; a suggestion is to list between 5-10. They are caused by other effects or causes. | Yes | All Effects incl. 'And' |
| Intermediate Effect | Effects that are neither negative nor positive on their own. They are caused by other effects or causes. | No | All Effects incl. 'And' |
| Desirable Effect | A wanted effect. We aim to reinforce these and eliminate negative consequences. They are caused by other effects or causes. | No | All Effects incl. 'And' |
| Given | Given entities are beyond your sphere of influence. They are sometimes called Preconditions. These always enter the tree without predecessors. E.g. Gravity is a given force unless you leave Earth. | No | All Effects incl. 'And' |
| Changeable | Changeable entities are those causes that can be changed and should be changed to mitigate the reoccurrence of problems. | No | All Effects incl. 'And' |
| And Junctor | In a sufficient cause diagram, each cause alone creates connected effects. The 'And' Junctor connects two causes, expressing that an event only happens if both causes are present. | No | All Effects (excl. 'And') |
Background Information on FRT Notation
FRT diagrams were developed as part of the Theory of Constraints by E. Goldratt. More on the Theory of Constraints can be found here.