Most artifacts have a single effect as their proper normative function. However, some artifacts achieve multiple effects, and their value lies in the combination of these effects. The Swiss Army knife is a prime example of such an artifact.
An artifact with the material features of a Swiss Army knife is, in principle, suited to achieve many different effects: cutting, tightening screws, opening bottles, filing nails, and more. Each of these effects results from specific use-plans that the artifact’s features are suited for, which satisfies the first condition of our normative function definition.
Individually, some of these effects do not constitute a reason for the artifact’s existence. For many of these effects, there are specialized artifacts better suited to achieve them. Consider the small scissors, for example. Although it is possible to cut things with these scissors, their placement and size make it slightly awkward to use the Swiss Army knife for this purpose.
However, the value of the Swiss Army Knife lies in its ability to combine multiple tools into a single, compact, and portable artifact. When we consider the composite set of effects, i.e., cutting, tightening screws, etc., it becomes evident that they do collectively constitute a reason, even the strongest reason, why it ought to be the case that we have access to an artifact such as the Swiss Army knife. Thus, this composite set of effects is the proper normative function of the artifact. This example illustrates how our normative function account accommodates artifacts whose proper function is to achieve multiple effects.