Custom System or Off-the-Shelf Software: How to Actually Decide
The right question is not which is better in general, but which parts of the business are actually different from everyone else's.
This decision is usually framed as a tradeoff between cost and fit: off-the-shelf is cheaper and faster, custom fits better. That framing is not wrong, but it skips the more useful question, which is where the business actually differs from a typical competitor.
Most operations are ordinary and benefit from ordinary software — accounting, basic inventory, standard scheduling. A handful of processes are usually where the real competitive edge sits: a pricing rule, an approval chain, a way of matching supply to demand that took years to work out. Forcing those into a generic tool's assumptions is where custom systems earn their cost.
A workable rule: buy the ordinary parts, build the parts that are actually distinctive, and resist the temptation to customise everything just because customisation is available. The businesses that regret custom systems are usually the ones that built what they could have bought.