Your result does not happen by chance. The Y=f(X) CascadeA structured brainstorming tool that breaks a high-level Y down into progressively specific, measurable Xs. Click term for full definition 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 in short
- Write your Y at the top. Use the metric from your goal, with a number: e.g. invoice error rate.
- Ask: what must be true?. What makes up the Y? This gives you level 2.
- Ask: what influences it?. Repeat for every factor, using your process map and data.
- Test every X. Is it specific, measurable and controllable by the process ownerThe person accountable for a process, who sustains the improvement long-term after the project ends. Click term for full definition?
- Mark your top Xs. Choose three to five critical XsThe small number of inputs that have the biggest impact on your output (Y). Also known as: Vital Few. Click term for full definition for your data collection planThe blueprint that defines exactly what to measure, how, and by whom, for both your Y and your Critical Xs. Click term for full definition.
Key points
- Y = f(X)The core Lean Six Sigma equation: your output (Y) is a function of multiple inputs (Xs). Click term for full definition: 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.