Adopt Over Adapt: The Case for Minimal Necessary Change
The most expensive implementations are rarely the ones with the wrong vendor. They are the ones where a capable platform was quietly reshaped, requirement by requirement, into a bespoke system with a vendor logo on it. Minimal necessary change is a different posture, adopt what the vendor does well, and only adapt where the business genuinely differentiates.
- 01
Start from the model bank, not the wish list
Every serious core, payments or wealth platform ships with a reference configuration that already encodes what the vendor considers good practice. Treat it as the default and force every deviation to earn its place. The wish list from a five-year-old business case is not a substitute for a modern reference model.
- 02
Separate genuine differentiation from historical accident
Most 'unique' requirements are not commercial differentiators, they are the shape of a previous system. Ask which requirements a customer would actually notice, which ones a regulator requires, and which ones only exist because the old platform could not do it another way. The last category is the cheapest thing to give up.
- 03
Price every customisation in whole-life terms
A customisation is not a one-off cost. It is a permanent tax on every upgrade, every regression cycle and every vendor conversation for the life of the platform. Score change requests against a fully loaded whole-life cost, not just the build estimate, and the shortlist of things worth changing shrinks quickly.
- 04
Change the process, keep the product
When a business process does not fit the model bank, the first question is not 'how do we customise the product?' but 'why do we do the process this way?'. Aligning the operating model to a well-designed reference is almost always faster, cheaper and less risky than bending a platform out of shape.
- 05
Govern deviations as exceptions, with a named owner
Every accepted deviation from the model bank should have a written rationale, a named business owner and a review date. Without that, small compromises accumulate into the same bespoke platform the organisation was trying to escape. Minimal necessary change is a discipline, not a slogan.
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