Short answer
Buying SaaS gives a fast start and ready-made support for standard processes; building your own software is valuable when a differentiating product or business model needs special control. Decide by time to first value, total cost, data control, flexibility to change and exit cost together.
Buying a product
An existing service can offer quick adoption, support and regular updates for standard processes. Test package limits, exports and integrations with a real workflow.
Building a product
Custom control may be useful for a distinctive product or business model. Budget for maintenance, reliability and continuity of the development team as well as initial investment.
What to compare
Use time to first value, total cost, data control, change flexibility and exit effort. A custom integration layer on top of SaaS is also a possible approach.
Decision record and exit plan
Write the decision with its reasons: the chosen path, the rejected alternative, the accepted risk and a date to review. If you chose SaaS, also write the exit plan (data export, alternative tool); if you chose to build, write the ownership plan (who maintains it, continuity if the team changes).
A hybrid option: an integration layer on top of SaaS
A third path is to use a ready-made SaaS as the core and complete only the narrow gap with a custom integration or module. It keeps the development load small while meeting the specific need, but it requires verifying the SaaS's interface, extension and contract limits up front.
Compare before deciding
Fill in the table below for both options; rows left empty show the unknowns you need to prove before deciding.
Frequently asked questions
Two questions we are often asked on this topic.
Does it make sense to try SaaS first and build later?
Often, yes. Validating the need quickly with a ready-made tool shows what is genuinely special. If you test data export and exit terms from the start, the later migration is easier too.
How is total cost compared?
Calculate set-up, integration, operation, change and exit cost for both options over the same period. See the guide SaaS total cost of ownership for details.
Sources and further reading
