We limit ourselves to one domain, the high power (approx.10 MVA) and high voltage (3-12 kV) converter so that we keep focused on a specific power electronic field.
The challenge is to make the product as specified (as per target requirement specifications) and keep budget, time-line as planned. Is it possible? It is, when taking enough margins during the planning phase. Remember that the margins have a cost.
So, if a certain activity was finished in budget and time and even fulfils the specifications, one can deduct that the margins were possible generous or correct.
The art of product development is not defined in text books, technical articles or standards. It comes with the designer experience and his/her team. In my eyes it is similar with cooking. Everything needs to be fine-tuned, in good harmony and aesthetics. At the end of process just ask the "design team"- do you like what you have done?
The end of the process is a piece of hardware that can be sold at the planned volume (pcs. per year), at the correct gross-margin and will be market accepted for 20 years and more.