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When it comes to project management, the words probability and possibility sound phonetically similar but could not be more different. These terms are all too often considered synonyms or are confused, at the project manager’s own peril. Consequently, the designation is something every project manager should familiarize themselves with, because each impacts risk management and tackles uncertainty differently. Here to help make sense of all this is a description of probability vs. possibility in project management.

Risk and Uncertainty

While the concept of risk involves uncertainty, the opposite is not necessarily true. Risk is essentially an impromptu event or occurrence that imparts a negative or positive impact to a project or objective. Conversely, uncertainty is simply a lack of certainty. While some people think this concept applies to undiscovered risks, that is not at all what it means. Rather, uncertainty is a complete lack of substantive information pertaining to a particular event, even though that event has been previously diagnosed. For example, unknown risks can occur despite a project manager possessing the necessary background information required to identify the risk, they are simply missed during the risk identification stage. This is precisely where possibility and probability come into play.

Definitions and Differences

Think of possibility as a qualitative system. It labels values by ordinal assessments, such as designations like low, mid and high. This is an ordered set that does nothing to indicate the differences between each component. Consequently, “possibility” is inherently subjective, leaving little room for objectivity. Whereas possibility is an inherently qualitative system, probability is just the opposite. Probability measures outcomes through quantification. This involves weighing a number of factors before finalizing a measurement. One good way to think about this and remember the difference between the two terms is to consider the difference in grading artwork vs. grading a math paper. One ultimately involves a purely subjective viewpoint whereas the other adheres to a strict set of measurements that can be replicated from task to task.

Implementing Both in Project Management

More qualitative methods of evaluation leave little room for quantitative analysis. This could have detrimental results in terms of project risks. For this reason, most risks are gauged using ordinal methods, completely ditching the concept of qualitative analysis altogether. Rather than having fluctuating data without any indication of why the data was recorded that way, quantitative risk management allows potential risks to be ordered in terms of funding requirements or outright alleviation. This is the kind of information available through the use of Clarizen’s cloud-based platform, which empowers business owners by providing powerful risk management tools that are as dynamic and sophisticated as today’s modern business atmosphere demands.


In terms of probability vs. possibility, probabilities undoubtedly provide more insight into the problems they are describing. They are typically used when the information they are analyzing is incomplete. Indeed, having complete information would negate the use of both qualitative and quantitative forms of analysis altogether. In other words, there would not be any reasons for uncertainty. This is inherently problematic, since the object being measured is risk itself, which is primarily based on uncertainty because it applies to future occurrences.