payback period (simple payback)

Payback period is the most intuitive measure of investment recovery: how many years does it take for the project's annual net cash flows to sum to the original capital outlay? The calculation is: Payback Period = Initial Investment ÷ Annual Net Cash Flow (for projects with level cash flows), or the year at which cumulative cash flows turn positive (for projects with uneven cash flows). A recycling plant that costs Rs 2 crore to build and generates Rs 50 lakh per year in net cash flow has a payback period of 4 years. Because payback is simple to calculate and understand, it is the first financial metric most Indian MSME entrepreneurs use when evaluating a new business or expansion — before IRR, NPV, or DSCR are even considered.

Typical payback periods for Indian recycling businesses: Plastic mechanical recycling (PET/HDPE): 2–4 years; Plastic film recycling (LDPE/PP): 3–5 years; E-waste recycling: 2–4 years for urban units with good feedstock; Tyre pyrolysis: 3–6 years (highly variable based on oil yield and selling price); CBG plants: 5–9 years (longer due to higher capex and slower ramp-up); Lithium battery recycling: 3–7 years (wide range — depends heavily on cobalt/lithium market prices and royalty structure). Projects with EPR credit revenue streams shorten payback significantly — a plastic recycler earning both pellet revenue and EPR credits may achieve a payback 1–2 years shorter than the same plant without EPR credentials.

Limitations of payback period as a decision metric: (1) it ignores the time value of money — Rs 50 lakh received in Year 4 is worth less than Rs 50 lakh received in Year 1; discounted payback period addresses this by discounting each year's cash flow before summing; (2) it ignores all cash flows after the payback point — a project with a 4-year payback and then 15 more years of strong cash flows is ranked equally with one that stops generating cash in Year 5; (3) it does not account for working capital needs, which can extend effective payback substantially for businesses with long receivable cycles (e.g. OEM customers paying on 60-day terms); (4) it can favour small, quick-payback projects over large, strategically important ones. For these reasons, payback should be used alongside IRR, NPV, and DSCR for complete investment appraisal.

In Indian bank loan appraisals, payback period is not a primary metric used by lenders (DSCR is) but appears in the DPR's executive summary as a readability measure for non-financial stakeholders. For PMEGP and KVIC subsidy applications, the DPR format specifically requires payback period in the financial summary. A payback period above 7 years is a red flag in these applications — it signals either high capex or low profitability and typically requires explicit justification for the government scheme assessor.