Final answer:
The non-qualitative factor is the Variable cost per unit of the product, as it's quantitative; whereas factors like quality, manufacturing deadlines, and potential loss of trade secrets are qualitative and impact the buy or make decision.
Step-by-step explanation:
The factor that is not a qualitative factor that Atlas Manufacturing should consider when deciding whether to buy or make a part used in manufacturing their product is C. Variable cost per unit of the product. This is because variable costs are quantitative in nature, as they refer to costs that change with the level of output, which can be measured and expressed in numerical terms.
On the other hand, qualitative factors include the quality of the outside producer's product, manufacturing deadlines and special orders, and the potential loss of trade secrets. These focus more on aspects that are subject to judgment and experience, rather than being easily measurable. For instance, quality refers to the non-physical aspects, like the skills in production or the technology employed by the external supplier, which may not be directly quantifiable. Similarly, issues like the potential loss of trade secrets can significantly impact the company's competitive advantage and are considered qualitative.