Start with the assumption that you should buy

A packaged product carries the cost of development, maintenance, security patching and compliance across many customers. For a common problem, that is very difficult to beat by building.

The honest test is whether your process is genuinely different from the industry norm, or merely familiar. A great deal of perceived uniqueness is historical accident, and adapting to a good product is cheaper than encoding the accident in software.

The cost of the gap

The case for building usually emerges from the gap. A product covers eighty per cent of the workflow, and the remaining twenty per cent is handled by exporting to a spreadsheet, rekeying between systems, or a rule that lives in one person's head.

That manual bridging is a real, recurring cost that rarely appears in the comparison. It is worth measuring, because it is frequently larger than the licence saving.

  • Time spent moving data between systems by hand
  • Errors introduced by rekeying, and the effort to correct them
  • Work that stops when one particular person is unavailable
  • Reporting that cannot be produced because data is fragmented

The middle path is usually best

The most common good answer is neither pure build nor pure buy: keep the packaged systems of record, and build the specific connective layer and interfaces your process needs on top of them.

This keeps the expensive, commoditised functionality bought, and spends custom development only where your business genuinely differs.

What building actually commits you to

Custom software is an ongoing commitment, not a one-off purchase. It needs maintenance, dependency updates, security attention and someone who understands it. Any honest comparison includes that.

It also produces something you own and can change on your own timetable, which for a genuinely differentiating process is often exactly the point.

Key takeaways

  • Default to buying; make custom development justify itself
  • Measure the manual work currently bridging the gap — it is the real comparison
  • Buy the systems of record, build the connective layer
  • Include ongoing maintenance in any build decision