# OT observation worksheet

Version 1.0 · October 2026 · Dan Fisher / danfisher.dev
CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/
Reuse/adapt with attribution and identify changes.

Use this with a simulation, a prepared training dataset, or an environment you are authorized to observe. This is a learning worksheet, not an operating or safety procedure. Do not put credentials, personal data, or private access details in a shared copy.

## 1. Understand the purpose
- Exercise / process name:
- What useful outcome is the process supposed to produce?
- Is this simulated, recorded, or currently observed?
- Observation date or dataset revision (keep private where appropriate):
- What is in scope? What is explicitly out of scope?

## 2. Follow one value
- Measurement and physical meaning:
- Units / valid range:
- Source and controller role:
- Display role and historian role:
- Where are sample time, receipt time, and quality available?
- How would you recognize old or missing data?
- What would an operator incorrectly conclude from the number alone?

## 3. Follow one action
- Action / command:
- Who is allowed to request it?
- Which component decides whether it can happen?
- What permissives or conditions must hold?
- What confirms an actual outcome rather than just a request?
- What should happen after a stop, loss of data, or restart?

## 4. Draw the relationships
Sketch process → controller → display / historian. Add command arrows separately.
Label logical trust boundaries without copying real access endpoints into a public diagram.

## 5. Separate evidence from assumptions
| Question | Expected observation | Actual observation | Evidence reference | What this does NOT prove |
| --- | --- | --- | --- | --- |
| Does the display respond? | | | | |
| Does the process behave as expected? | | | | |
| Are the measurements fresh? | | | | |
| Is history actually collected? | | | | |

## 6. Explain the lesson
- One thing observed:
- One assumption corrected:
- One unanswered question:
- What would you test next, and with what authorization?
- What would you remove before sharing this worksheet?