- Applying the decision rules
Each method has a clear accept/reject and ranking rule.
Once the appraisal figures are calculated, apply the decision rule for each:
| Method | Accept / reject | Ranking (choose) |
|---|---|---|
| Payback | within the target period | the shortest payback |
| ARR | above the target return | the highest ARR |
| NPV | positive | the highest NPV |
| IRR | exceeds the cost of capital | the highest IRR |
So a single project is judged on whether it meets each rule; competing projects are ranked by each measure. The first step in any decision is therefore to state clearly what each method says — e.g. 'NPV is +$15,000 (accept); payback is 3.5 years (within the 4-year target); ARR is 18% (above the 15% target)'. Quoting the figures and applying the rules turns the calculations into the basis for a decision.
- Payback: within target / shortest.
- ARR: above target / highest.
- NPV: positive / highest.
- IRR: above the cost of capital / highest.
See the full worked example for investment decisions and recommendations using supporting data →