Investment appraisal: what it is

· Investment appraisal = methods used to assess whether a capital investment project is worthwhile.
· Used to compare investment opportunities by focusing on costs, returns, time, and sometimes risk.
· In exams, always link the method to the business context: cash flow position, speed of return, profitability, and long-term value.
· A project may look attractive on one method but weak on another, so strong answers explain why results may conflict.

Payback period

· Payback period measures how long it takes for a business to recover the initial cost of investment from net cash inflows.
· Decision rule: the shorter the payback period, the more attractive the project is, especially when liquidity is important.
· Formula idea: Payback period = time taken for cumulative cash inflows to equal the initial investment.
· If the exact year is not reached neatly, calculate the fraction of the year needed using the remaining amount still unrecovered.
· Strengths: simple, quick, useful for businesses worried about cash flow, risk, or fast-changing markets.
· Limitations: ignores cash flows after payback, ignores overall profitability, and ignores the time value of money.
· Exam insight: choose payback when the business has limited cash, faces high uncertainty, or wants a fast return.

This image shows a payback period graph where cumulative cash inflows recover the original investment between two time periods. It is useful for seeing why payback may fall partway through a year, not exactly at year-end. It reinforces that payback focuses on speed of recovery, not total return. Source

Average rate of return (ARR)

· Average rate of return (ARR) measures the average annual profit from an investment as a percentage of the average investment.
· Core formula: ARR = average annual profit ÷ average investment × 100.
· Decision rule: the higher the ARR, the more attractive the project is.
· ARR focuses on profit, not cash flow, so it gives a different perspective from payback period.
· Strengths: considers profitability, easy to compare as a percentage return, simple to understand.
· Limitations: ignores timing of profits, ignores cash flow, and ignores the time value of money.
· Exam insight: ARR is useful when the business wants to judge expected profitability, but less useful if the key issue is liquidity.

This image shows a worked ARR spreadsheet layout with investment cost, yearly returns, and the resulting percentage return. It is helpful for visualising how ARR turns projected profits into a comparable percentage. Use it to remember that ARR is profit-based rather than cash-flow-based. Source

This diagram shows how future cash flows are discounted back to present values. It helps explain why NPV gives less weight to cash received later in the project. This is central to understanding why NPV can rank projects differently from payback or ARR. Source

This image shows a worked NPV calculation with annual cash inflows, discounting, and a final present value result. It is useful for seeing how NPV is built from multiple discounted cash flows over time. In exams, this supports interpretation of whether an investment adds value overall. Source

Comparing the methods

· Payback period focuses on speed of cash recovery.
· ARR focuses on average profitability.
· NPV (HL only) focuses on value created after discounting future cash flows.
· A project with a short payback may still have a low ARR or low/negative NPV if later returns are weak.
· A project with a longer payback may still be better if it gives higher total profits or higher NPV.
· In evaluation, do not say one method is always best; explain which is most suitable for the business’s objectives and financial situation.

This image gives an overview of major capital investment decision tools. It is useful for seeing investment appraisal as a comparison between different decision criteria rather than a single formula. This helps when writing evaluative exam answers about why different methods may lead to different choices. Source

How to interpret results in exam questions

· Always identify the best project according to the method used, then explain why.
· Refer to the business context: cash shortages, risk, rapid technological change, need for profitability, or long-term strategy.
· Strong evaluation often includes a judgement such as: payback is better for short-term survival, whereas ARR/NPV may be better for long-term return.
· If figures are close, mention that the final decision should also consider qualitative factors such as risk, market conditions, strategic fit, and the accuracy of forecasts.
· Watch the difference between cash flow and profit: this is a common exam trap.

Common exam mistakes

· Confusing profit with cash inflow.
· Forgetting to calculate cumulative cash inflows for payback.
· Choosing the project with the highest ARR without checking whether the question instead prioritizes liquidity or speed of return.
· For HL, forgetting that NPV discounts future cash flows and depends on the discount rate.
· Giving formula-only answers without any interpretation or business judgement.