Before writing a single line of code, it's worth answering one question honestly: what is the manual process actually costing you today?
Start with time, not features
It's tempting to start a project by listing features. A better starting point is estimating the hours per week your team currently spends on the manual version of the task: data entry, status chasing, reconciling two spreadsheets, answering the same question over email.
Multiply that by an hourly cost estimate, and you have a rough baseline for what the current process costs per month. That number is what any proposed tool needs to beat.
Account for error cost, not just time
Time isn't the only cost. Manual processes also produce mistakes: a missed appointment, an inventory count that's off, a client who didn't get a follow-up. These errors often cost more than the time spent on the process itself, in the form of lost trust or lost revenue.
A simple gut-check
If a proposed tool would take three months to pay for itself in reclaimed time and reduced errors, it's usually a strong candidate. If the payback period stretches past a year, it's worth asking whether a smaller, more targeted fix would get most of the benefit for a fraction of the cost.