Investment Viability Index is a structured way to assess whether a borrower’s proposed investment or expansion is likely to generate enough benefit to justify the funding. In MSME underwriting, it may consider project cost, expected revenue, margin improvement, payback period, capacity utilisation, promoter contribution, market demand, and execution readiness. For example, buying a new machine may be viable if confirmed orders, power capacity, skilled labour, and margin improvement support the plan. The index matters because term loans for expansion can fail when assumptions are unrealistic or implementation is delayed. The caution is to avoid treating the score as a final answer; supporting documents, sensitivity analysis, promoter track record, and post-disbursement monitoring are still required.