While NPV is a powerful tool, it has limitations. Firstly, NPV relies heavily on accurate cash flow projections and discount rates; a small error can significantly skew results. Additionally, NPV does not account for project scale. A larger project might have a higher NPV than a smaller one, but the smaller project could yield a better return on investment. Furthermore, NPV doesn't consider the potential flexibility or managerial options that might arise during a project's lifecycle. Finally, businesses may find NPV calculations complex and time-consuming, especially when comparing multiple projects with varying lifespans or cash flow timings.

Yes, a project can have multiple IRRs, especially when cash flows alternate between negative and positive values more than once. In such cases, the IRR equation can have multiple roots, resulting in multiple discount rates that make the NPV zero. This phenomenon complicates the use of IRR as a sole investment appraisal tool. When multiple IRRs exist, the NPV method can provide clarity. By plotting NPV against different discount rates, businesses can identify where the NPV becomes positive or negative, aiding a more informed investment decision. This is known as the NPV profile.

Taxation directly impacts a business's cash flows, and it's essential to account for it when determining NPV. When estimating future cash inflows and outflows, the post-tax amounts should be used. Any tax shields, such as the tax-deductible depreciation, should be included in the cash flows, as they enhance the project's net cash inflow. By incorporating taxation, the NPV provides a more accurate representation of the net benefits the business can expect to derive from the investment, post all tax obligations.

Inflation affects the purchasing power of money; thus, it's crucial to consider it when forecasting future cash flows for NPV calculations. If a business expects inflation to rise, the future cash flows must be adjusted to represent their reduced purchasing power. Not accounting for inflation can lead to an overestimation of future benefits, resulting in a higher and potentially misleading NPV. When the discount rate is chosen, it should incorporate the inflation rate to reflect the real time value of money. Failing to adjust for inflation can lead to incorrect investment decisions, as the project's real profitability might be over- or underestimated.

The NPV method is favoured by many businesses because it considers the time value of money, effectively quantifying the worth of future cash flows in today's terms. Unlike the Payback Period, which only identifies the time required to recoup an initial investment, NPV provides a more comprehensive assessment of a project's total profitability over its entire lifespan. Additionally, while IRR determines the rate at which the NPV becomes zero, NPV offers a direct monetary value that can be easily compared with other potential investments, aiding clearer decision-making. Moreover, NPV is less susceptible to distortions and offers a more unambiguous evaluation when compared to the IRR in projects with non-conventional cash flows.