# How can a Goal Tree help you changing job? Part 3/5 –  List and order all prerequisites using necessity-based logic

This is the third post of my series How can a Goal Tree help you changing job? After refining the personal Goal statement (Part 1) and identifying the Critical Success Factors to achieving the Goal  (Part 2), it is time to build the Goal Tree with all prerequisites – Necessary Conditions – using necessity-based logic.

In order for you to understand or clarify the difference between Necessity-based logic and sufficiency-based logic, I invite you to read my post Goal Tree Chronicles – Enablers vs.triggers

# Listing the prerequisites and building the Goal Tree

The Goal and the Critical Success Factors (CSFs) make the top of the Tree. From this very basic structure, it is necessary now to list and order sequentially which conditions must be fulfilled in order to enable each Critical Success Factors.

As already mentioned in part 2, in order to be a surgeon, it is mandatory to complete a MD degree. The MD degree is an enabler to be a surgeon, alternatively called a Necessary Condition or an Intermediate Objective on the way up to the Goal.

Without the enabler, no way to achieve the related objective, in our case: without the MD degree, no way to be a surgeon. Yet a Necessary Condition fulfilled doesn’t mean that it is sufficient for the objective to be met.

Again, if you’d like to understand or clarify this important difference, please read Goal Tree Chronicles – Enablers vs.triggers.

The Tree building is about listing all mandatory enablers from the Goal down to the basic conditions, step by step. The “magical sentence” to help this process is “in order to… I/we must…”

• In order to be a surgeon, I must be awarded a MD degree,
• In order to be awarded a MD degree, I must pass successfully all exams, enroll in Medical School and…
• probably fulfil other Necessary Conditions that must be clarified.

In the process of building the Tree, some padding and rearrangement will be necessary. It’s okay to start with the biggest milestones and iteratively straighten the Tree by inserting the missing Conditions or rearranging those already listed.

Remember, the recommended use of sticky notes may let the draft of a Goal Tree look like a brainstorming exercise, which it is not. Brainstorming is about creativity, Goal Tree is about rational, necessity-based logic analysis!

For the purpose of building a personal Goal Tree, which will provide personal guidance and isn’t meant to be shared, it is not that important that this Tree is absolutely logically sound and robust. An approximate Goal Tree is acceptable in this case.

Of course, I would absolutely not tolerate any ambiguity, wrong wiring in the sequence description nor poor logic in the case of facilitating a strategic or tactical Goal Tree built for an organization!

Nevertheless, although it may be for personal and private guidance it is better to have a well-built Tree with enough details, e.i. NCs, simply because it will be useful for later steps. Thus, investing some time upfront building the Goal Tree may pay nice “interests”, i.e. save time later.

## How do you know you “reached the bottom”?

A recurring and legitimate question from beginners: how do I know I developed my tree deep enough? The simple answer for a personal Tree is as soon as you feel at ease with the details. If you feel like needing more, go deeper. If you feel comfortable with what you have, you may stop.

In case of a shared Tree, my answer would be: stop as soon as you describe something everybody knows or if you hit the point where the content is part of someone’s job. He or she knows what to do as a professional and doesn’t need a description of his/her trade.

## A simple but powerful way to check a prerequisite

When an entity is suggested as a Necessary Condition (a prerequisite), it must make sense when reading aloud the full sentence “In order to achieve (the objective), I/we must have/achieve (Necessary Condition)”. If it makes no sense or is weird, the it is not a NC of poorly verbalized.

If the match is good, test the following: put your hand so to mask the NC and ask aloud “without (Necessary Condition) no way to have/achieve (the objective)”. If the answer is a strong yes, the chances are that this entity is a real prerequisite are quite high.