Risk means probability of failure,risk can be positive or negative in the context of environment and uncertainty is due to lack of information at times. Quantitatively and qualitatively risk can be measured.Economy and social factors are driving any startup.Balanced scorecard could be the better tool for tracking business.

the entrepreneur should have a business plan and model as roadmap.

a lot of growth projections are done from this.

and it would be apparent what the risks and uncertainties are from this.

In contrast to uncertainty, risk can be studied and analysed. A good start-up knows its risk profile. Regarding the question what variables are good risk indicators, the answer depends on which risk we are talking about. When talking about credit risk (risk of default), the typical indicators are credit ratings or any variables typically used by credit agency, such as leverage ratio, debt amount, growth rate, etc. Especially for start ups, operational risk (risk related to business operation) tends to be quite low (exceptions exist) but liquidity risk (risk of not having liquid assets when needed) tends to be high. Possible variables for those are rate of automatisation, realised cost due to legal disputes; or ratio of liquid to non-liquid assets and many more. I'm not trying to list every possible risks with every possible measures. The point is you need to identify concretely what kind of risk first, then find measures appropriate to it.

On the other hand, measuring uncertainty is a very difficult task, since it is not observable. I will refer to the Knightian uncertainty principle. Uncertainty is not measurable in contrast to risk. While trying to identify uncertainty is the ideal way to understand a business, having to deal with uncertainty is a real pain. When your goal is to measure the probability of success or profitability or even growth, incorporating uncertainty will only bias your result. However, when the ultimate goal is to identify the worst possible case in the business, then uncertainty is something to deal with.

dont see why uncertainty cant be measured/ measurable. it depends on the dimensions you use.

Brian Barnard , it is simply because (Knightian) uncertainty is defined that way. While the word itself may refer to events with particular probability, this may not be differentiable from "risk". Frank Knight (1921) refered "uncertainty" as fundamental uncertainty, i.e. the limit or lack of knowledge. "Uncertainty" is a notion to describe black swan events, while "risk" does not. This is per definition unmeasureable.

If you still disagree, I am genuinely interested on your suggestion how to measure uncertainty.

knightian uncertainty may be defined that way, but it does not imply business uncertainty is purely knightian.

in mainly cases it is possible to delineate ranges for the factors you are uncertain about.

the objective is to manage risk, not to mitigate completely surprising/ unpredictable events.

black swans are not startups' biggest concern.

Without making this question about the difference between risk and uncertainty, I will refer to existing discussion on risk vs uncertainty in another RG question and its useful comments.

https://www.researchgate.net/post/What_is_the_difference_between_risk_and_uncertainty

given that the most prominent factor here is likely sales or income/ profit, note what a typical profit distribution would look like for a SME, and then expand it to a progression over a number of years...

Thanks for your answers @ Brain Barnard, Christopher Imanto and Abhay Patil. Prof. Knight stated that risks (also known as foreseeable risks) are associated with probabilities while uncertainties have no probabilities because they are Unforeseeable risks and should be the main function of an entrepreneur (to bear them).

My opinion is that with insurance even the uncertainty risks can be taken care of or transferred.