Risks are commonly assumed to be the same as uncertainty in the area of风险管理. Although there is a big difference between risk and uncertainty, many professionals often think they are the same.
尽管从PMP或PMI-RMP考试的角度来看，这个概念并不重要，但您必须理解差异以避免混合它们。
Therefore, I’m writing this blog post to explain it and I hope after reading it, you won’t have any problems distinguishing between risk and uncertainty.
Risk
A risk is an unplanned event that may affect one or some ofyour projectobjectives if it occurs. The risk is positive if it affects your project positively, and it is negative if it affects the project negatively.
负面的否定性和积极因素有单独的风险反应策略。
The objective of anegative risk response strategyis to minimize their impact or probability, while the objective of a正风险反应策略is to maximize the chance or impact.
You might also hear two more risk terms: known and unknown. Known risks are identified during the identify risks process and unknown risks are those you couldn’t identify.
Acontingency planis made for known risks, and you will use the contingency reserve to manage them. On the other hand, unknown risks are managed through aworkaroundusing themanagement reserve.
Uncertainty
不确定性是缺乏完全确定性。在不确定的情况下，任何事件的结果都是完全未知的，并且不能衡量或猜测。您没有有关活动的任何背景信息。
Uncertainty is not an unknown risk.
In uncertainty, you completely lack the background information of an event, even though it has been identified. In the case of unknown risk, although you have the background information, you missed it during the identify risks process.
A Real-World Example of Risk and Uncertainty
Assume two famous teams consist of renowned players, and they are going to play a football match the next day.
Can you tell me exactly which team is going to win?
No, you can’t; however, you can make an educated guess by reviewing and analyzing the past performances of each player, the team, and the results of matches they played against each other.
Then you can come up with some numbers like there is a 30% chance of Team A or Team B winning, or there is a 70% possibility of Team A or Team B losing the match.
现在，让我们在不同的情况下进行相同的足球比赛。
Let us say again that two teams are going to play a game, and no players are selected for either team.
在这种情况下，如果有人问您要赢得哪支球队，您的回应将是什么？
You will be clueless because you don’t know which team consists of which players, and you have no idea how the teams will perform.
Here, you don’t have any information on past performance, and cannot predict the outcome of the event, even though the rules and the stadium are the same.
This situation is called uncertainty.
Risk Vs Uncertainty
以下是风险和不确定性之间的一些差异：
- In risk, you can predict the possibility of a future outcome, while in uncertainty you cannot.
- Risks can be managed while uncertainty is uncontrollable.
- Risks can be measured and quantified, while uncertainty cannot.
- You can assign a probability to risks events, while with uncertainty, you can’t.
Conclusion
Risk and uncertainty are different terms, but people tend to confuse them. Managing risks is easier because you can identify them and develop a response plan based on your experience. However, managing uncertainty is very difficult, as previous information is not available, too many parameters are involved, and you cannot predict the outcome.
However, to complete your project successfully, you must be very cautious, proactive, and open-minded to manage risks and uncertainty.
这就是风险和不确定性的帖子结束。我何pe now you can distinguish uncertainty from risk. Still have some doubts, post them in the comments section and I will reply to you.
by identifies risk and I must proactive to the uncertainty event by doing this my project will be successfully doing.
You should be proactive in risk management. It will surely help you complete your project successfully.
Mathematically
Risk = an uncertain event if occurs can impact the outcome of event in a positive or negative direction
所以它有两个部分
Risk = Probability * impact
Now under probability theory an event can occur in three ways
1) It will happen ( a certain event) prob = 1, impact you can input based on your findings to find Risk
2) It may occur ( a probable event, however small it could be, those who talk about unknown unknowns or uncertainties all fall here) the probability could be infinitesimal or we just ignore it as It’s not worth * impact = get the risk value .
3）不会发生（不可能发生的事件，零概率） *影响=无关的风险。
外面没有什么。这些不确定性甚至我们可能不会想到或想象也将属于它，但只担心可能影响我们项目的主要可能事件。
Your life has millions of variables all uncertain, even lightening striking us may have a probability, but we don’t really consider it Day to Day risk, but those who are not so lucky and it get struck , despite infinitesimal probability they loose.
Every single event whether known and unknown has a probability of occurrence and it sums up to 1.
Now you choose what your sample space is?
Well said Vinod.
对不起,我不同意y的基本定义ou are using. To begin with, uncertainty is an umbrella term to define any known or unknown event or series of events. It encompasses Allowances, Contingency and Risks. Allowances are “known-knowns” whose exact value is not known at the time but whose expenditure is certain to occur. Hence an amount is assigned to this particular cost, and later revisited when additional information becomes available. Contingencies are “known-unknowns,” within the defined project scope. It is a specific provision for unforeseeable elements of cost within the defined project scope, particularly important where previous experience relating estimates and actual costs has shown that unforeseeable events that increase costs are likely to occur (AACEI). Contingency event estimates are made based on experienced judgment from subject matter experts (SMEs)on that estimate. Risks are the “unknown-unknowns” whose probability of occurrence and cost impact is not certain. But even the unknown-unknowns can be estimated by SMEs, based on their experience using Monte Carlo computer models to estimate the probability of occurrence and an estimated value of the impact. The Risk Register is where the risks (or opportunities) are listed and discussed in a Risk Workshop of SMEs, and both qualitative and quantitative descriptions are assigned to each risk element. The risk elements are prioritized, and the SMEs then look for mitigation measures to reduce or eliminate each risk. The residual post-mitigation risks are then used as the basis for the Monte Carlo computer analysis. The analysis will return the calculation that there is a (say) 80% probability that the total cost of the risks will be less than $ X thousand, or other percentages and impact cost depending on the risk estimator’s (or management’s) risk appetite. This amount should be added to the Project Base Cost (which would include Allowances) and the Contingency, defined as the Project Baseline Cost, to arrive at the project funded (or budgeted) cost.
For a more complete treatise on Uncertainty which I co-authored, please read “Addressing Uncertainties in Cost Estimates for Decommissioning Nuclear Facilities,” © OECD 2017, NEA No. 7344.
这些定义基于PMBOK指南第五版。bob手机客户端
除非你们已经决定，除非您已经决定项目管理的不确定性定义与其他人类努力（如科学，工程和医学）的定义不同，否则我建议阅读有关该主题的众多书籍中的一些。当然可以测量不确定性，并在严重的领域中使用，以分配结果将在定义范围内发生的概率。
Google uncertainty in science or uncertainty budget
I fear you may have got some of your info from the field of economics (which can make astrology and black magic look bad) ;)
Can you explain it little further:
当然可以测量不确定性，并在严重的领域中使用，以分配结果将在定义范围内发生的概率。
Thanks for sharing the ideas about risk and uncertainty. What Angel says is not different from your right and simple idea to make it clear. The difference is only in the statement but you both have presented the same difference eithet it is quntifiable or not which clears the fundamental difference between them. Thanks for making me more clear on the subject matter.
In uncertainty you completely lack the historical and pas information. The construction of a house or painting a wall does not fall in this category. Here you can estimate the cost will a good accuracy. Most of the times these contracts are given under fixed price or cost reimbursable.
在风险下，您可以猜测结果，但在不确定性方面做不到。
有人可以告诉我风险和不确定性的关系吗
Risk can be said to be an uncertain event which chances of occurrence can be predicted and measured whereas, uncertainty can also be said to be an uncertain event which chances of occurrence cannot be predicted and measured. The difference is that the probability of a risk event happening can be predicted and measured while the probability of uncertainty cannot be predicted and measured.
FAHAD
我们可以说，应对负面风险的应急计划，而管理储备专用于不确定的问题，因为我们无法猜测它们的影响？
This is a tricky question.
As per my understanding, since the uncertainty is a identified risk, you can passively accept the uncertainty and keep some contingency reserve based on educated guess.
我还要求其他访客分享他们对此的想法。
Risk: We don’t know what is going to happen next, but we do know what the distribution looks like.
Uncertainty: We don’t know what is going to happen next, and we do not know what the possible distribution looks like.
Correct….
In my view uncertainty is imperfect knowledge. Throughout a project we strive to improve definition (reduce uncertainty) to improve chances of success (reduce risk of failure.) There are key uncertainties in projects that you must understand well before making strategic decisions.
Cost estimating is a good example to illustrate uncertainty.It is very difficult (if not impossible) to estimate the final cost of a complex project to the last cent. Do you remember what happened the last your did a remodelling job at your house? If you did not understand the uncertainty well, you may end up regretting the decision of remodeling the kitchen yourself. That is why you do the front end work: develop the scope, prepare the plans, get quotes, etc. it is to reduce uncertainty.
不确定性分析有助于我们了解结果的预期范围和针对项目目标的测试，以做出明智的决定。例如，我们可以测试一个项目是否对各种成本增长方案有弹性，并做出明智的决定来制裁该项目。然后，我们可以表征风险或机会。
Sorry to add confusion but I agree fundamentally with Angel. .
Lets suppose we have to paint a wall in our kitchen.
最初（在计划阶段）我们不确定要使用的油漆量，但可以估计它是一个随机数
We are uncertain of the time it will take to paint the wall .
There is a risk that the plaster will fall apart in preparation.
There is a risk that the paint will bubble after it has been applied.
不确定性是通过研究来管理的，并将Slack投入项目
Negative Risk is managed by process improvement and recovery strategies.
Incidently you can have uncertainty about the likelihood of a risk event occuring :)
Hi Fahad,
Can you please help in providing details/difference of Perform Qualitative and Quantitative risk analysis?
谢谢，
纳文
In Qualitative risk analysis, you prioritize the risks by multiplying their probabilities and impact. And in Quantitative risk analysis, you numerically analyse the risks. Here, you find the cost of each risk (if it occurs individually) and then you add it up to get the overall effect on the project.
Thanks a lot !!!
Both risk and uncertainty are inevitable in today’s scenario of Project Management. one has to driven his path midway.
Yes, one has to chose the best path suitable to the project.