Certified Production & Operations Manager Exam Practice 2025 – Complete Study Guide

Random variation refers to fluctuations in a process that are inherent and occur naturally, often due to unforeseen or uncontrollable factors. This type of variation is characterized by its unpredictable nature and is typically the result of numerous small, random influences that cannot be easily traced to a specific source or cause. Because these variations happen without any consistent pattern or influence from management decisions, they fall outside the realm of managerial control.

In contrast, assignable variation can be traced to identifiable causes and is therefore subject to managerial intervention. Environmental variation often pertains to external factors that may influence a process but can sometimes be managed or mitigated by managers. Processed variation refers to variations that arise during the operational processes, which can also be addressed by managerial actions. Thus, the essence of random variation lies in its unpredictability and intrinsic nature, making it a type of variation that managers typically cannot influence.