Production factors exploited are among others materials, used work-in-progress, applied production resources (machines), and the human workers executing the activities.

Biffl, S., Gerhard, D., & Lüder, A. (2017). Introduction to the Multi-Disciplinary Engineering for Cyber-Physical Production Systems. In Multi-Disciplinary Engineering for Cyber-Physical Production Systems (pp. 1-24). Springer, Cham. [Springer]