---
title: Y=f(X) Cascade
description: "Your result does not happen by chance. The Y=f(X) Cascade breaks it down into the factors behind it, so you know exactly what to measure. Watch the short video, then work with the toolkit PDF: it explains the method, shows…"
url: "https://skillagility.com/en/resources/y-f-x-cascade/"
updated: "2026-10-07"
category: 02 MEASURE
---

# Y=f(X) Cascade

Your result does not happen by chance. The Y=f(X) Cascade breaks it down into the factors behind it, so you know exactly what to measure. Watch the short video, then work with the toolkit PDF: it explains the method, shows a worked example and gives you a blank template to fill in.

Tool video

The short tool video will appear here.

[Y-f-X-Cascade_Toolkit_EN](https://skillagility.com/wp-content/plugins/embedpress/assets/pdf/web/viewer.html?&file=https%3A%2F%2Fskillagility.com%2Fwp-content%2Fuploads%2F2026%2F10%2FY-f-X-Cascade_Toolkit_EN.pdf#key=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)

## Y=f(X) Cascade in short

1. **Write your Y at the top.** Use the metric from your goal, with a number: e.g. invoice error rate.
2. **Ask: what must be true?.** What makes up the Y? This gives you level 2.
3. **Ask: what influences it?.** Repeat for every factor, using your process map and data.
4. **Test every X.** Is it specific, measurable and controllable by the process owner?
5. **Mark your top Xs.** Choose three to five critical Xs for your data collection plan.

Key points

- Y = f(X): your result depends on its inputs.
- Break Y down level by level.
- Every X must be specific, measurable, controllable.
- Pick the critical few for data collection.

**Related tools:** [CTQ-Tree](https://skillagility.com/en/resources/ctq-tree/) · [Data Collection Plan](https://skillagility.com/en/resources/data-collection-plan/) · [Detailed Flowchart](https://skillagility.com/en/resources/detailed-flowchart/)