2.009 Product Engineering Processes


Specifications are used to define and measure product success. They translate customer needs into quantitative design performance targets and quantify the core benefit of a product. Specifications can provide a basis for resolving trade-offs and help keep the development effort focused.

A specification is a precise description of what the product must do; it is not an embodiment or a way to implement the product.

A specification consists of a metric (a quantifiable property or behavior), a unit, a value, and an owner. It is often tricky to write specifications. Examples are provided in course lecture notes.

In this in-class exercise, each team section was given a "product" (in this case, fruit) and a kit of tools to explore the product's attributes. The groups were tasked with developing specifications consistent with the product. These specifications were then given to another group for assessment (without knowing the identity of the fruit); groups interpreted the specifications, and identified products that met them. At the end of the exercise, some results were presented and critiqued in front of the class.

Some sections did a better job of generating attributes and corresponding metrics than others. The more successful groups listed quantifiable properties for their metrics, appropriate units and realistic values, while less successful groups tended to list embodiments (e.g. color, weight), inappropriate units (or things other than units!) and uninformative values.

See examples of some better (and worse) specifications from the exercise!

Fruit/team pairing list