Physical prototypes are invaluable there is no doubt of that. Just like any other tool, they can be dangerous in the wrong hands.
In the past i have seen personnel from other disciplines within an organisation see a prototype as proof of manufacture, sales and or profit.
Obviously these are undesirable side effects and must be managed.
Any new concept apart from being an absolutely brilliant idea must also make a profit, produce a quality item that sells, all within a reasonable time-frame and developmental cost.
A working prototype is not proof of sales, profit, or time to market, a team of people understanding all aspects of the project from concept to full scale production is.
A thorough understanding of all costs both developmental and ongoing are crucial as is proof of manufacturability final quality and sales potential.
Many projects fall over due to misunderstandings between suppliers and the company.
There are many hurdles to overcome between concept and sales.
Often concept to prototype is swift and cost effective, the journey from there to profitability is fraught with hundreds of miscommunication's and misunderstandings.
The author has found that multi-disciplined teams work best, where a good mix of experience and expertise are essential.
All elements of any team are equally important, so often organisations make the mistake of not recognising that.
Quality is as important as sales, technical due diligence is as important as financial management.
Tying the team together takes good management and needs to encourage lateral thought and entrepreneurial spirit.
A team must have quality time tested experience of all aspects of its journey from prototype to profit if its going to succeed.