- 2065 Chaitra · 4 marks
Define certainty, uncertainty and risk
Short answer
Certainty means outcomes are known exactly. Risk exists when possible outcomes and their probabilities are known, enabling expected value analysis. Uncertaintiy occurs when probabilities are unknown or outcomes are not fully defined, requiring judgement and sensitivity analysis.
Define the concept of certainty, uncertainty and risk.
Certainty
Certainty means that the outcome of a decision is known exactly in advance: the cash flows, lives and interest rates are known with no doubt. Example: a bank fixed deposit of Rs 1,00,000 at 10% will give exactly Rs 1,10,000 after one year. Standard engineering economy techniques (PW, AW, IRR) assume this condition.
Risk
Risk exists when the outcome is not certain, but all possible outcomes and their probabilities are known or can be estimated (from past data or experience). The decision maker can then use expected values and variance. Example: a machine will give annual savings of Rs 50,000 with probability 0.6, Rs 30,000 with probability 0.3 and Rs 10,000 with probability 0.1, so the expected saving = 0.6(50,000) + 0.3(30,000) + 0.1(10,000) = Rs 40,000.
Uncertainty
Uncertainty exists when more than one outcome is possible but the probabilities cannot be estimated reliably (or even the outcomes are not fully known). The decision is made using judgement, sensitivity analysis or rules such as maximin, maximax and minimax regret. Example: the market response to a completely new type of product, or the effect of future government policy.
| Basis | Certainty | Risk | Uncertainty |
|---|---|---|---|
| Outcomes | One, known | Several, known | Several, may be unknown |
| Probabilities | Not needed (p = 1) | Known | Not known |
| Tool | PW, AW, IRR | Expected value, decision tree | Sensitivity, scenario analysis |
In practice most engineering projects are decided under risk or uncertainty, because they are based on forecasts.
✓ Answer checked by Claude Opus 5.5 (high effort)
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