When a global professional services firm acquired a specialist European team, the deal was done, but the integration was not. The new team continued operating on their own legacy systems, separate from the rest of the firm, and these systems became increasingly difficult to support. What should have been a temporary workaround became a long-term risk. Harmeston Consulting was brought in to project-manage the post-merger integration effectively, this time across technology, process, and people.

The objective was straightforward but far from simple. The acquired team needed to move onto the firm’s standard case management platform so they could work in the same way as colleagues across the UK, Europe, and Asia. This meant retiring a legacy system that had never been properly assessed during acquisition and replacing it with something fully supported, integrated, and future-ready.

Just as important was protecting the team’s day-to-day work. Data had to be preserved, disruption kept to a minimum, and users needed to feel confident that the change would actually make things better, not harder.

The legacy system created problems on multiple levels. It ran on unsupported infrastructure that internal IT teams could not maintain, leaving the business reliant on external support and unable to evolve. The data itself was rich, detailed, and structured very differently to the firm’s existing systems, making migration complex and high risk.

There were also human challenges. The team had been used to working with few constraints and a lot of autonomy. The new platform introduced structured workflows and rules that felt restrictive at first. Even when those changes were positive, they required people to work differently, which naturally led to resistance.

Earlier in the programme, the firm had attempted to solve the problem by introducing a brand-new third-party system for everyone. After extensive testing, it became clear that the solution simply did not meet the firm’s needs. Making the call to stop, exit the contract, and change direction was difficult, but necessary.

Harmeston focused first on understanding how the acquired team actually worked before initiating any business change. Detailed process mapping was carried out to capture real workflows and identify where the legacy system supported them and where it did not.

Once the decision was made to move onto the firm’s standard platform, the project was delivered in controlled phases. Multiple test data conversions reduced risk, while a deliberately hands-on training approach gave users time to build confidence. Extended access to a pilot environment, refresher training before go-live, and on-site support immediately after launch helped ensure adoption was supported rather than forced.

The team is now live on the firm’s standard case management platform and operating on fully supported infrastructure. The legacy system has been retired, internal IT teams can provide ongoing support, and the acquired group is no longer operating in isolation.

While adoption is still bedding in, the long-term benefits are clear. The team is now positioned to integrate with firm-wide document management, external filing authorities, and future cloud platforms. Costs have reduced through consolidation, visibility has improved, and the firm has finally completed the merger it started years earlier.

Most importantly, the organisation now has a platform that supports growth rather than holding it back.