Use SaaS when your workflow is standard. Consider custom software when the operating model itself is the differentiator or integrations and controls become unusually specific.
The decision is not about whether custom software is more impressive. List the workflow, users, integrations, reporting requirements, regulatory constraints and expected growth. Then test whether available products cover the important requirements without excessive workarounds.
If an existing product solves 85–90% of the workflow and the remaining gap is not strategically important, buying is often the more rational choice.
SaaS cost includes subscription fees, implementation, data migration, integration and process change. Custom software cost includes discovery, development, hosting, maintenance, security, support and the responsibility to keep improving it.
Compare total cost over a realistic horizon, not only the first invoice.
A warning sign is when staff must maintain side spreadsheets, copy data between systems or create unofficial workarounds because the purchased system cannot represent the real operation. At that point, the organisation may be paying for software while still carrying manual-system risk.
Before commissioning custom software, verify that the unusual workflow should actually remain unusual. Sometimes the software is exposing a process that should be simplified.