Development , Testing , Delivery

so does it really make sense to create 5 different products instead of reassuring if the base of the product keeps track of the goal?

@erroronline1 In ideal world, sure. I personally never worked on a product that has a proper shape from the beginning. Clients like to change their mind and even rebuild from scratch if the business requirements change.

@erroronline1 you're thinking too literally. Think of it as one product that always does the job but gets more impressive each iteration.

@LynxMagnus that indeed makes sense. but i still find the analogy to the car more meaningful because it is a constant development of one product. it might make little sense to show a client just the wheel like 'look at my fancy and well structured database queries!' though.
if the clients face is not happy because the car has no roof despite being able to drive i consider it their faulty expectations. like claiming the missing wallpaper during an inspection of preliminary building works. beside the possibility of faulty promises what to expect from the sneak preview.

No, not like that one either.
It's exactly my former boss, starts from "no more than a calculator app", ends with an app that should read some weight values from a digital scale over network, fetch some data for each value from its sqlite db (which should export/import data, also including blobs for pics), calculate a sophisticated receipt out of these all, make a pdf out of the receipt, connect to a Bluetooth printer and print the receipt. He also kept asking for a "rough estimate", and I was like "First you tell me WHAT THE HELL DID YOU EXACTLY SOLD?"

So it makes sense to build prototypes, but it should be seen in the design that it's just a prototype. So that the common core of subsequent versions would not be just an abstract idea like "the concept of riding" or "the concept of calculating", as the customer would expect. This way you may have the core functionality, but each version is probably a totally different product. Rather, what should be common in versions is technically similar concepts, like reusable components, as a designer could foresee. IMO an ideal design would treat different releases as prototypes which are/contain also reusable components.