Four Assumption Rules for straight arrows A-B, B-D, A-C, and C-D’
Rule 1 – Referring words
(1) The statement after “because” should contain some words that clearly refer to the “in order to” part of the statement, and some to the “we must” part.
(2) Make sure that the assumption is bringing in “the third party” (a NEW element/agent/object/factor) – “TRIANGLE”.
Rule 2 – Explain the link, not the entity
(1) Check that the assumption will not be just a repetition or an expansion of one of the entities.
(2) Check that the statement in the assumption would not be stating “To achieve what?/For what?”
Rule 3 – If we want… and if… then we must
(1) The sentence makes sense.
(2) Additional check: Is the statement after “and if” really different in meaning from the statement after “if”, or is it just a variation?
Rule 4 – What is the current prevailing mechanism?
What is the current prevailing mechanism through which we achieve what is stated after “in order to” as related to what is stated after “we must”?
Rules 1 and 2 are used for developing assumptions and for checking assumptions that have been surfaced and recorded.
Rule 3 is only used for checking.
Rule 4 is only used for developing.
EVERY developed assumption must go through the check of Rules 1, 2, and 3. To be accepted as a valid assumption, it must pass the check of all three rules.
Source: Jelena Fedurko, Mistakes and Difficulties in Working with TOC Logical Tools, 2014