ERP programmes aren't difficult. They're delivered poorly.

I recover ERP programmes that have gone wrong, and I provide assurance on the ones that haven't yet. The failure modes barely change. The first is executive support, and what it actually means in practice.

Everyone knows no project succeeds without executive support. Fewer people can say what it looks like on an ERP programme. In my experience it comes down to three behaviours.

1. Be realistic, and make it safe for others to be realistic

I've watched an executive overrule a project team on a 200+ entity implementation. Twelve months and $2–3 million, in his opinion. No historic data, no bottom-up estimate, no basis beyond wanting it to be true.

On another, a project team told me they couldn't give their CFO the real forecast cost. They'd be chewed up for it. So they made a number up.

Same failure. Fear at the top becomes fiction underneath, and by the time the fiction collapses you are too far into delivery to fix it.

So how do you know your team is being realistic? Ask what the number is built on. There are three good answers:

• a fixed price selected through competitive tender;
• real cost and duration from a comparable implementation;
• a bottom-up estimate from the people who will do the work.

One on its own is thin. Two that agree is a plan. And if the honest figure is one you don't like, that is a conversation about whether to proceed at all. Have it before you commit to contracts and licences, not after.

2. Champion it. It needs your people, not just your budget

Future-state design, data migration, testing and cutover consume the business, not IT. Supporting an ERP programme is not something people do around the day job. It is a full-time job. Second people into the programme and backfill them.

For a finance implementation that means a named representative for each process area: record to report, accounts receivable, accounts payable, fixed assets and EPM.

Skipping this is a false economy. You either pay for backfill, or you pay for delay while the programme burns hundreds of thousands a month waiting on people too busy to show up. Backfill is cheaper.

3. Be patient about transformation

Executives want transformation from day one. But moving ERP is enormous on its own. Push for transformation on top and you are asking the business to re-imagine itself while changing the wheels at 100mph.

Your process leads also have no idea what the new system can do. They've sat through the demo. That is not the same as using it, living with it, breaking it. Only then can they tell you where the real opportunity is.

Get it in. Take the standard process. Hold the line on customisations. Stabilise. Then go hard at the improvements once you are live.