The assignment discusses the limitation and merits of payback period and net present value (NPV) methods in project evaluation. Valco plc chooses site A over site B based on NPV calculations, despite similar payback periods. The article highlights the importance of considering current business environment changes and accurate discount rates to avoid selecting non-viable projects. It concludes that firms must control expenses, use break-even analysis to identify profitable sales levels, and employ project evaluation methods like NPV to choose viable projects.