Modernizing complex legacy systems is never easy, especially when years of customization and workarounds have become embedded in daily operations. That was the situation facing this client, a safety equipment assembler and distributor serving government entities across the Great Lakes region. Running on a heavily customized legacy system, they struggled with inefficiencies, unreliable processes, and mounting risks.
The company’s business model combines both assembly and distribution of components, serving primarily government entities. They were operating on a heavily customized 2016 version of Microsoft Dynamics NAV, which had become increasingly difficult to manage. Staff were forced to closely monitor processes to prevent errors, reducing both efficiency and confidence in the system. Over time, they developed a patchwork of quirky workarounds that became embedded in their daily operations.
The organization had originally implemented NAV years earlier with another reseller but was currently relying on an independent consultant for ongoing support. While this arrangement worked for a while, it eventually broke down when the consultant could no longer provide adequate support and decided to retire. Without a reliable partner, the client was left vulnerable and without a clear path forward.
Additional challenges included the lack of an integrated shipping system, which forced reliance on manual steps and disconnected tools to manage fulfillment. This not only slowed operations but also increased the potential for errors in order handling and delivery.
One of their most significant operational hurdles involved their complex bill of materials (BOM) requirements. They needed to explode BOMs on quotes and orders to adjust component lines while still maintaining the summary header and rolled-up information. Standard NAV, Business Central, and most other ERP systems did not support this requirement, forcing them into inefficient manual adjustments or a need for customization.
When the organization began exploring modernization options, they evaluated several ERP platforms, including Microsoft Dynamics 365 Business Central, NetSuite, and Infor. Ultimately, the choice came down to Business Central, with The TM Group (TMG) as their implementation partner.
With guidance from TMG, the client implemented Microsoft Dynamics 365 Business Central as their core ERP system, along with Cosmos for enhanced financial reporting and Dynamic Ship from Insight Works for integrated shipping. This modern platform addressed long-standing inefficiencies and created a reliable, scalable foundation for growth.
The key focus of the implementation was to resolve the client’s complex bill of materials (BOM) requirements. In standard Business Central, exploded BOMs remove the header line, making it impossible to view rolled-up costs and margins. TMG custom developed a new line type that preserved header-level values—including quantities, margins, and calculations—while still allowing detailed component adjustments. This ensured accurate quoting, reporting, and invoicing. To further strengthen margin analysis, TMG also added a custom reference cost field, giving the client a static baseline for profitability tracking.
TMG also had to reconfigure document copy functionality, ensuring that copied documents carried over the custom header-level calculations such as percentages, margins, and reference costs. In addition, the team built functionality for attaching certifications and CAD files, allowing documents to be uploaded at the line level, flagged in the system, and printed automatically with sales orders in the correct sequence.
To support flexible inventory item requirements, TMG also enhanced the handling of “non-stock items.” These temporary items could be quickly created and adjusted, but once designated as standard inventory, they were locked down to maintain control and data integrity. This balance ensured agility for buyers while protecting long-term record accuracy.
Another critical component was system security and financial data privacy management. Previously, the client maintained multiple NAV companies to prevent users from accessing sensitive information. TMG consolidated these into a single Business Central environment and delivered an advanced security model using Microsoft 365 security groups with table-level filters. This approach restricted access to sensitive GL accounts, vendors, and other sensitive information, while streamlining user setup across eight security roles such as sales, purchasing, warehouse, and finance.
Although the scope of security and permissions grew larger than initially anticipated, the final solution provided a structure that balanced flexibility with control. By addressing complex needs—ranging from BOM exploding enhancements and reference costing to certifications, CAD files, non-stock item workflows, and data security—TMG replaced fragile workarounds with stable, automated processes. The client now operates on a modern ERP system that supports compliance, efficiency, and scalability for the future.
Business Central, combined with integrated reporting, shipping, and certification management, has strengthened financial controls, improved efficiency, and provided a secure foundation for growth. With a scalable platform and a trusted partner, they are now well-positioned to adapt and thrive as their business evolves.
They have also moved away from the limitations of their heavily customized NAV system and the costly, disruptive upgrades that came with it. Business Central’s extension-based architecture ensures that updates and new features can be applied seamlessly without rewriting custom code, allowing the organization to stay current with Microsoft’s twice-yearly major releases and monthly fixes. Instead of facing complex upgrades every 5 or so years that cost tens of thousands of dollars and risked breaking functionality, they now benefit from continuous improvements in the cloud. This not only reduces IT overhead and eliminates the burden of maintaining on-premises hardware but also provides a more reliable, future-ready platform that supports efficiency, innovation, and growth.
One of the key factors in this project’s success was the collaborative approach the client brought to every interaction. Rather than expecting TMG to deliver all the answers, they consistently engaged as a true partner—brainstorming, troubleshooting, and adapting alongside our project team. Even under stress, they maintained professionalism and self-awareness, which fostered a positive, solutions-oriented environment. Their willingness to quickly involve the right people also kept the project moving forward, ensuring decisions could be made without delay.
Another lesson was the value of thorough User Acceptance Testing (UAT). The client invested more time in UAT than any other project the TMG team had seen - months of detailed testing, feedback, and refinement. While some issues still surfaced after go-live due to some departments not being as thorough, the extended UAT process gave them a far stronger foundation than most projects. This diligence demonstrated the importance of taking the time to test, retest, and validate processes before committing to go-live.
The project also underscored the reality that even with an intent to stay as close to “vanilla” Business Central as possible, business complexity often drives customization. Despite their best efforts, the client ended up with a heavily customized BC system because their users demanded functionality equivalent to what they had in NAV—particularly around BOMs and costing. However, because the customizations were implemented through extensions in BC, they remain sustainable and compatible with Microsoft’s upgrade model.
Leadership played a pivotal role as well. The CFO was deeply engaged throughout the project, often leading UAT efforts himself, retesting changes, and working side by side with his users. His active involvement and advocacy ensured alignment across departments and gave the project credibility from the top down.
Finally, the client’s mindset toward quality over deadlines was a refreshing change. Unlike many organizations that rush to meet arbitrary go-live dates, this client prioritized having a stable, well-tested product. They were willing to extend timelines and evaluate costs if it meant achieving the right outcome. This patience and commitment to quality significantly contributed to the project’s long-term success.
Key takeaway: Projects succeed most when clients are collaborative, thorough in testing, open to change, and led by engaged leadership. Prioritizing quality and user adoption over arbitrary deadlines leads to better outcomes, stronger partnerships, and systems that truly fit the organization’s needs.
This project illustrates how even the most complex legacy environments can be successfully modernized with Microsoft Dynamics 365 Business Central when paired with the right partner. By addressing challenges around BOMs, costing, certifications, and security, TMG delivered a system that not only streamlined operations but also positioned the client for long-term growth with a secure, scalable platform.
If your organization is considering a move to Business Central—or if you’re struggling with outdated customizations and costly upgrades—The TM Group can help. With decades of experience and a proven track record of successful implementations, we’re ready to guide you every step of the way.
Contact us today to learn how we can support your journey to a modern, future-ready ERP.