Welcome to the Community, Mark.

Tracking assembly items is unavailable in QuickBooks Online. You might want to check online if there's a third-party application you can use.

I'll also send this feedback to our product engineers for future updates.

If you want to track your services or non-inventory items, check this article: https://community.intuit.com/articles/1883552.

You can always drop by if you got more concerns.