Concept Models, Prototypes and First Articles

by Tom Weltner

When developing an idea for a new product, a representative physical sample is often desirable.  Physical models are useful in advancing product design.  Further, physical models can be very effective in communicating a design concept, particularly to nontechnical team members or investors. 

The product development staff at PPI has many years of experience in product development, and has participated in numerous product development teams.   Based on our experience, we have learned the value in making a distinction between Concept Models, Prototypes and First Articles.

The Concept Model

As the name suggests, a concept model is used to communicate the main concept of the envisioned device.  The concept model may be a working model, or it may be inert.  It may be of a larger or smaller scale than the conceived product.  One could readily imagine how pipe cleaners and Popsicle sticks could be used to communicate how a new thoracic retractor might work. Even though nonfunctional, this model could help determine handle length, grip angle and fulcrum points.  If the results still appear promising, the next iteration might be fabricated by a local craftsman in full scale.  However, it might make sense to make a few expedient compromises to hasten the project schedule and reduce cost.  For instance, the craftsman may have a ready supply of low cost steel.  This material is not biocompatible, but since it is recognized that the device is not ready for clinical trials anyway, the savings in schedule and cost may be justified.

The Prototype

Typically, the conclusion of a product development effort is the fabrication of one or several prototypes of the desired device.  The prototype fully represents the complete and final design in as great of detail as possible.  Within the practical limits of cost and schedule, the prototype fully represents the design, materials, quality, function, finish, etc. that is expected from production units.  They are frequently made by hand or in very small quantities by highly skilled craftsmen using low-volume manufacturing techniques.  Ideally, prototype units are fully qualified for clinical trials.

First Articles

First Article devices (sometimes called pilot production devices) are the result of early phase production.  They are the first units off the assembly line, and fully represent the result of production tooling, methods and work instructions.  They should be very similar to prototype units.  First Article units are typically subjected to close scrutiny and inspection to ensure that they are fully compliant with engineering drawings and technical specifications.