A dedicated product engineering methodology will take the following aspects into account:
• Putting the customer in charge: There is one central entity in charge of the overall process. This is the customer, who is the authority defining the intended functionality and operating constraints of a given product.
• Providing all required knowledge: A comprehensive knowledge-base, that covers all required knowledge from all phases of the process, will be provided for each of the participants.
• Permitting a smooth transition along the chain: There will be support for a smooth transition between the process steps without the danger of misunderstandings or loss of knowledge. This will consist of thoroughly defined interfaces and tools.
• Supporting global participation: There will be support for an operation that is independent of time and location of the individual participants.
The Pretzel model is particularly suited to support a customer-driven approach to product engineering, as it shows a way of how to introduce the necessary technology knowledge into the process that can usually not be assumed to be available to the customer in the required depth.
The Pretzel model: interwoven top-down and bottom-up flows in product engineering.