What is Decision Tree?
A decision tree lays out choices, uncertain events, and possible outcomes in sequence. When branches have defensible probabilities and values, expected value can help compare paths while keeping the assumptions visible.
When to use it
Use it for choices with multiple paths and uncertain outcomes when you can estimate probabilities and values.
How the methodology works
Build a tree of decisions and outcomes with probabilities and values to calculate the optimal path using expected value analysis.
- Start with the decision and draw each available action as a branch.
- Add chance outcomes after actions. Use probabilities and values that have a defensible basis, consistent units, and a clear time horizon.
- Enter outcome values on the same time and unit basis, then compare the resulting paths and test uncertain inputs.
Example: Choosing whether to pilot a new service
Illustrative situation: Hypothetical only: a business can launch immediately or run a limited pilot. The pilot could show enough demand to expand, or too little demand to continue without revising the offer.
How to apply it: Map launch-now and pilot as separate choices. From the pilot branch, show the expand and revise-or-stop outcomes. Add probabilities and values only when the team can explain their basis, then treat expected value as an estimate under those assumptions, not a forecast.
Example limits: This scenario is illustrative, not evidence about a real business. Use evidence relevant to your decision for your own facts, ratings, probabilities, or financial estimates.
How to read the result
The recommended path is the one with the highest expected value under the probabilities and values you entered.
Questions about Decision Tree
When is a decision tree more useful than a decision matrix?
Use a tree when later choices depend on uncertain outcomes that happen first. Use a matrix when comparing several options against the same criteria is the main task.
Does the highest expected value guarantee the best choice?
No. It depends on the probabilities and values entered and may not reflect risk tolerance, cash constraints, or strategic considerations.
What should I check before comparing expected values?
Make sure each chance node covers the relevant outcomes, probabilities are based on evidence, and values use a consistent unit and time horizon. The result is only as reliable as those inputs.
Next step
Write the first decision, then add the outcomes that could follow each choice before estimating probabilities or values.
Need a printable resource or a step-by-step method? Business decision-making tools. Compare branching outcomes with weighted and financial decision methods.