Using QB for CPQ app?

Well let me weigh in with a random opinion. I have been working with Quickbase first as a kind of power user when I was a manager and then after we sold our family business as a developer, in all since 2002. so 20+ years.  I have worked with I imagine more than 100 clients and countless apps. And all I can say is when you get into the intricacies of building an app with crazy business rules, there's always a way to do it with QuickBase one way or the other.  

The famous Quickbase sales engineer Kirk Trachy, now retired had a great expression. "If you can say it, we can do it."   And what he meant by that is if you can clearly enunciate in words, the business rule or the formula or the restriction that you are trying to implement then we can do it. The challenge often becomes being crystal clear about what the requirement is.   

We have so many tools now at our disposal compared to the early days. Pipelines, formula queries, URL Formula buttons and regular old relationships.

So for example if I was to guess what you meant about your original question, if we are building an order and it has Child Line items the order can easily detect through very conventional summary fields whether or not there are any child items in category windows.  That would allow us to control whether or not we will let you add another child item as tinting.  Simply be a form rule which blocks the safe and put up a message to the user. "Cannnot I add tinting because no windows yet".    

David,

I've created several inventory and estimating forms for our business. Managing all the fields and actions can be a bit tricky, but once you get the hang of it, they work really well.The trick is always to build for scale.  I've learned how to do this on my own, mostly through trial and error.

If you're already using Quickbase, it's convenient to have everything in one place, in a familiar environment. However, I wouldn't recommend it for beginners unless your system is super simple and won't change much or often.

In my experience, formulas tend to be more dependable than form rules. Both have their uses, but I've found that formulas consistently give better results.

I hope this information is helpful!