Why RSGx cancelled a 7-figure Microsoft Dynamics contract mid-implementation

About RSGx

• Mechanical and electrical engineering and construction services across Australia
• Close to A$500m revenue, seven years after launch
• 13 group entities, including acquisitions and joint ventures
• Finance stack: Xero, Mayday, Employment Hero, Procore, dataSights and Power BI

"Mayday is your ticket to an indefinite Xero future."
Andy Colalillo, CFO, RSGx

Does a $500m, 13-entity business need an ERP?

In March 2026, two months into RSGx's Microsoft Dynamics implementation, the project sponsor walked into CFO Andy Colalillo's office at 6:30pm. The team had finished scoping and spent weeks in detailed design workshops. Andy asked him how he was feeling about the project. They looked at each other. "Do you want me to be honest?" Andy said yes, and they both blurted out the same concerns. Neither was convinced they were on the right path.

They had started the project for the reason most growing businesses do. Once RSGx passed $200m in revenue and 10 entities, an ERP felt like the obvious next step.

"If we're going to get bigger, for people to take us seriously, that's just what companies do."

Andy doesn't think that thinking was wrong at the time. RSGx delivers engineering, construction and commissioning for road, rail, power, water and data centre projects across every Australian state, mostly for tier-one contractors and joint ventures. It turned over close to $30m in its first year, then $60m, $120m and $240m. Today it's close to $500m.

New entities followed the growth, often, as Andy admits, without a whole lot of strategy: one for an offering, one for a project, one for a state. The group rationalised down to four, then acquired four or five businesses and formed a string of joint ventures. It now runs 13 entities.

Some gaps were real. To build a procurement function, Andy needed one consistent contact list. With separate Xero organisations, he'd be maintaining 13. Consistent contact management went on his list of reasons for an ERP. After 12 months of selection and scoping, RSGx began implementing Microsoft Dynamics in January 2026, with a 7-figure contracted cost.

Upgrading to an ERP felt like “going back in time 15 years”

A bigger investment should buy better tools. For RSGx, it bought older ones.

Reporting showed it first. RSGx runs its monthly P&L reviews and board meetings live in Power BI. Nothing is printed, and nobody works from a fixed pack. The team explores the numbers together in the room, drilling into whatever the conversation needs. Microsoft Dynamics offered configured, static reports, and getting anything close to that flexibility was, in Andy's words, "rubbish."

"The reporting was just going back in time 15 years."

Changing those reports came at a price. In 2026, the implementation partner quoted $45k to configure four standard reports: remittance advice, purchase orders, tax invoices and goods receipts. Andy asked for something out of the box. "I said to the implementation partner, what the actual F? It can't be that complicated. Why does it cost this much? And the answer was literally, “well, that's what we charge."

The same rigidity ran through the rest of the system. Andy expected some structure, and a business of RSGx's size needed a degree of it. What worried him was being locked into configurations in a business that moves quickly and will reverse a decision it thinks is wrong.

Microsoft Dynamics did much of what it was sold to do, and Andy is fair about that. It just couldn't compare with the software RSGx already used.

"The reality was highly disappointing compared to the SaaS solutions. Not just Xero, but your Maydays, your Employment Heroes. Anything built in the last few years."

RSGx was already running an ERP-grade finance tech stack

Andy joined when the business was six months old and had closed two month ends. He set up the chart of accounts, GL structure and P&Ls in Xero, built reporting in Power BI and Spotlight, and introduced disciplined budgeting and forecasting long before the business reached scale. That visibility helped him win the banks' support.

The stack grew around Xero one function at a time. Employment Hero handled payroll for a large blue-collar workforce. After six months struggling with a complex industry-standard project management tool, the team switched to Procore and had it running in four weeks. The project that prompted the switch ran for three years and delivered $50m of revenue. dataSights became RSGx's data lake and the base for its consolidation and reporting.

Mayday came through an introduction from Kevin Wiegand at dataSights. Andy signed up for intercompany reconciliations and chart of accounts consistency across the group. "When I looked at the cost of that solution at a company at scale, and what it did, it was a no-brainer." But with the ERP project under way, he didn't use it for much else. "We were already one eye on the ERP journey."

Pulling the plug on the year-long ERP project

While the ERP implementation went on, the reasons for it started to disappear. Contact management arrived in a Mayday product email while it was still one of Andy's main reasons for Microsoft Dynamics. Three or four more gaps closed the same way, most of them through Mayday.

"The email marketing was actually annoying me. The gaps from what you needed an ERP for in a multi-entity business were just evaporating."

How contact sync works in Mayday‍

In a group with separate Xero organisations, every entity keeps its own contact list. In Mayday HQ, you choose a primary organisation, and Mayday compares every other entity's contacts against it, flagging contacts that are missing or have inconsistent details. You can create a contact across every entity at once, fill in gaps, or edit the primary contact and push the change to the rest of the group. Bank details are still set in Xero, which keeps the audit trail and permissions intact, and Mayday then syncs them across the group. When you save, every change is written back to Xero.

Close management followed. The Microsoft Dynamics partner estimated two to three weeks to configure a month-end checklist tool. Andy trialled close management through Mayday and had it connected and working within an hour.

Around the same time, Andy got in touch with Jack Thiel, Mayday's APAC commercial lead, who introduced him to CFO Techstack's Finance Leader Advisory Council. Its first in-person session took place in Sydney a week later.

That was the backdrop to the 6:30pm conversation. After half an hour with his project sponsor, Andy called RSGx's owner and CEO that same night. The CEO has invested in software businesses before and could see how quickly AI was changing software development. "I said, listen, this is what I'm seeing, this is what I feel. He said, Andy, I agree with you. What do you want to do? I said, I'm going to pause it. He said, go for it." The call took 20 minutes. "We're getting to scale," says Andy, "but we're still nimble."

A month later, RSGx formally cancelled the seven-figure Microsoft Dynamics implementation. By the time it told the wider business, the team had replaced the ERP plan with the RSGx tech stack, built on Xero, Mayday and its other core tools. The business took it in its stride. "We don't have people who've been in roles for 20 years that are averse to change," says Andy. "The business actually just went, yeah, get it, no problem."

Everything the ERP promised, on Xero

RSGx cancelled Microsoft Dynamics partway through implementation without losing any capability. "At no point were we not able to do what we needed to do in terms of reporting," says Andy.

Mayday now covers the gaps that drove the ERP decision. Contacts and tracking categories sync across the group, giving RSGx one source of truth for suppliers and clearing the way for a procurement function. Intercompany reconciliations and chart of accounts consistency run across all 13 entities. Close management runs in Mayday, set up in an hour rather than weeks of partner configuration.

Walking away from Microsoft Dynamics saved RSGX a seven-figure-plus commitment in software and implementation. Month end changed too. Intercompany bank recs across the group used to take anywhere from a few hours to many at month end. Now the team reconciles and checks them in Mayday every day, in minutes.

"Mayday was the one that just said, that's no longer a problem, we can solve that for you."

Reporting stays live in Power BI and dataSights, and the board still explores the numbers together. The principle behind their financial tech stack is to use the best SaaS product for each business function and connect them with AI. Where no product fits, as with mobilisation and onboarding, RSGx now uses AI to build its own tools on top of what the market offers.

"We're building our own ERP, but by time and module. As opposed to trying to find something and jam ourselves into it."

For Andy, Mayday's pace is part of the value. "Seeing how quickly you guys move and how much you listen to your customer base is a huge part of what defines Mayday for me. If you're running multiple entities, it's a necessity."

Is an ERP on your team's roadmap?

RSGX's reasons for an ERP were real, but most of them turned out to be solvable on the Xero organisations it already ran. If an ERP is on your plan, it's worth checking which gaps still need one.

You might recognise some of these:

• You run several entities, each on its own Xero organisation
• Contacts, chart of accounts or tracking categories drift out of line across the group
• Intercompany and bank recs take hours at month end
• Your close depends on a checklist someone has to chase
• An ERP is on the plan because that's what businesses your size are expected to do

Start a 30-day free trial and run your next month end on Mayday. Your books stay in Xero, so there's nothing to migrate, and you'll know within a month whether you need to leave your ledger at all. If you're already comparing ERPs, book a call with one of our team and we'll go through your list of requirements with you.