Business systems

How to choose or replace an enterprise resource planning (ERP) system

A requirements, data, testing and cutover framework for small and medium organisations.

ERP selection should begin with business capabilities, transaction volume, exceptions, controls and ownership. Feature demonstrations come later and should use the organisation's difficult scenarios. Separate must-have outcomes from inherited workarounds, prove critical end-to-end scenarios with real complexity, and fund data, integration, change and cutover as first-class workstreams.

The decision

What changes the answer

  • The implementation partner's proposal should state assumptions, exclusions, responsibilities and acceptance evidence.
  • Data migration requires business cleansing and ownership as well as a technical import method.
  • A credible cutover has rehearsal, reconciliation, rollback criteria and operational support.

Where the decision commonly goes wrong

  • Selecting from feature count or brand alone
  • Customising a new system to preserve every old workaround
  • Leaving reconciliation and reporting until after go-live

A sensible way to decide

  1. 01

    Define the case for change

    Record current cost, risk, delay, controls and outcomes. Confirm what should not be changed.

  2. 02

    Map capabilities and exceptions

    Cover quote-to-cash, procure-to-pay, inventory, fulfilment, returns, finance, reporting and local obligations.

  3. 03

    Evaluate through scenarios

    Require shortlisted solutions to demonstrate the business's difficult transactions and integrations.

  4. 04

    Plan data and change

    Assign data owners, cleansing rules, training, process decisions and support.

  5. 05

    Rehearse cutover

    Run migration, integration, reconciliation and go/no-go steps before the final move.

  6. 06

    Stabilise after go-live

    Track defects, workarounds, reconciliation and support demand against exit criteria before closing the implementation programme.

Check before committing

  • Business case approved
  • Capabilities prioritised
  • Difficult scenarios demonstrated
  • Data owners assigned
  • Integrations tested
  • Cutover rehearsed
  • Reconciliation accepted

Material checked for this note

This is a general operational guide. Check applicable vendor documentation and professional advice before acting on a material decision.

Links and technical details checked 2 September 2026. Corrections can be sent to info@turnstoneai.com.

A practical next step

Apply the guidance to the real environment.

Share what is not working, what is changing or what decision needs to be made. Technical answers can come after the business context is clear.