VAVEhub · Toolkit 01

FAST Diagram Worksheet

Function Analysis System Technique — map WHY ← functions → HOW before touching a single idea.

Project / Product

Team / Facilitator

Date

Baseline cost

Step 1 · Identify functions (verb + noun)

Walk the BOM. For every component, ask: what does it do? Express each answer as an active verb + measurable noun. Classify Basic (why the product exists) or Secondary (how this design happens to do it).

Component	Verb	Noun	Basic / Secondary	Notes (all-time? required? esteem?)

Step 2 · Build the logic chain

Place the basic function just inside the left scope line. Moving right answers HOW?; moving left answers WHY?. Draw all-time functions (safety, esteem, regulations) above the main path. Sketch below:

scope line scope line · HOW → · ← WHY

Quality checks:

Every function is two words — if you need more, you're describing a solution, not a function.
Does the chain read correctly in BOTH directions (HOW → and ← WHY)?
Is there exactly one basic function path? Multiple = split the study.