What is Microsoft Dynamics SL (Solomon), and what should users do before support ends?

Microsoft Dynamics SL, formerly known as Solomon, is an on-premises ERP system designed primarily for project-driven businesses. It connects financial management with project accounting, job costing, time and expense tracking, billing, distribution, and related operational processes.

Dynamics SL has served project-based organizations for decades, but the product is now approaching the end of its Microsoft support lifecycle. Mainstream support has already ended, and extended support is scheduled to end on July 11, 2028.

For organizations still running SL, the question is not whether the system has served the business well. It is how long the current environment can safely remain in place, what risks increase as support winds down, and what options should be evaluated before the deadline.

What is Microsoft Dynamics SL?

Microsoft Dynamics SL is an enterprise resource planning (ERP) system that brings project management and financial management together in a single platform. Where standard accounting software struggles to handle project work, Dynamics SL was built specifically to connect the two, so project-based companies can track costs, bill accurately, and stay on budget from one system.

That focus is why SL became a favorite in industries where projects, not products, drive revenue. It is widely used across construction, government contracting, professional services, field service, and distribution, particularly by organizations with complex billing structures, tiered labor rates, or an offsite workforce to manage. For these businesses, the tight link between project accounting and the general ledger has long been the platform’s biggest draw.

Why is Dynamics SL also called Solomon?

Many longtime users still refer to the product as Solomon, and that name carries real history. Solomon Software launched in 1980 and spent the next two decades building a reputation for flexibility and customization in the mid-market accounting space. Great Plains Software acquired Solomon in 2000, and Microsoft then acquired Great Plains in 2001, folding both products into its growing Dynamics family. Microsoft eventually rebranded Solomon as Microsoft Dynamics SL, though the original name stuck with the people who had used it for years.

Today SL sits alongside other established products in the Microsoft lineup, including Dynamics GP, each with its own strengths and its own place in the platform’s history.

Key features and modules of Dynamics SL

Dynamics SL earned its niche by covering the full range of functions a project-driven business needs, all within one connected system. Its core modules include:

• Financial management: General ledger, accounts payable, accounts receivable, and cash management form the accounting backbone, with the reporting depth finance teams expect.
• Project accounting and management: This is the heart of the platform, giving teams job costing, budgeting, revenue recognition, and progress tracking that tie directly back to the financials.
• Time and expense tracking: Employees can record hours and expenses against projects, supporting project costing, billing, and related payroll processes.
• Distribution and supply chain: Order management, purchasing, and inventory features support the operational side of project and service businesses.
• Field service: Companies that dispatch technicians can manage service calls, contracts, and equipment from within the system.
• Payroll: SL handles complex payroll requirements, a common need for organizations with large or distributed workforces.

Because these modules share a single data foundation, information moves cleanly from a timesheet or purchase order all the way to a customer invoice and the general ledger.

Who uses Dynamics SL?

Dynamics SL fits a specific profile, and understanding that profile helps explain why it has stayed in use for so long. The platform suits mid-sized, project-based organizations that need their project data and their financial data to work as one. Companies with layered billing arrangements, multiple labor rates, or government compliance requirements have found it especially valuable, since these are exactly the scenarios that generic accounting tools handle poorly.

If your business bills by project, tracks profitability at the job level, and needs accounting and project management to stay in sync, you are the kind of organization SL was designed to serve.

Microsoft Dynamics SL end of life and support timeline

The most important thing to understand about Dynamics SL is where it sits in its lifecycle, because that shapes every decision you make from here. Microsoft has confirmed that SL is winding down, and the timeline is now fixed rather than theoretical.

Dynamics SL 2018 is the final major release and the only version Microsoft still supports. The table below lays out the key lifecycle dates so you can see the full timeline at a glance.

Because ERP evaluation, budgeting, migration planning, testing, and training take time, organizations should not treat July 2028 as the date to begin planning.

Running software past its support window carries real risk, including security vulnerabilities, compliance gaps, and the slow drift of your system falling behind the tools it needs to connect with. Microsoft’s own lifecycle guidance is straightforward, recommending that SL customers consider moving to Dynamics 365 Business Central, its modern cloud ERP and the natural successor for mid-market Dynamics users. When you are ready to make that move, our Dynamics SL to Business Central migration services guide the transition from planning through go-live.

Should you stay on Dynamics SL or migrate?

With the lifecycle clear, the practical question becomes whether to stay on SL for now or begin planning a migration. There is no single right answer, and the best choice depends on how well the system still serves you and how much runway you have before 2028.

Some organizations have good reasons to stay in the short term, and you may have room to plan a thoughtful transition rather than a rushed one if:

• Your current setup is stable and your customizations are working as intended.
• You are still on an active support or maintenance plan.
• Your team is productive and your reporting needs are being met today.

Other signals point toward moving sooner, and a migration should climb your roadmap if:

• You are hitting the limits of on-premises infrastructure and its maintenance costs.
• You are struggling to integrate SL with modern tools like Microsoft 365 or Power BI.
• Your team is losing time to manual processes that a cloud system would automate.
• You want to take advantage of Microsoft’s AI capabilities, such as Dynamics 365 Copilot, which help automate tasks and surface insights but are not available in SL.
• You want access to newer capabilities that SL will never receive.

Even if Dynamics SL is still working for your organization today, waiting until the support deadline is risky. ERP evaluation, budgeting, partner selection, implementation planning, data migration, testing, training, and go-live preparation can take months or longer, especially for project-driven organizations with complex billing, payroll, reporting, integrations, or customizations.

Planning early also gives your organization more control over timing and budget. Many companies need to secure budget approval well before a migration project can begin. Waiting until the last minute can compress the timeline, limit testing, increase disruption, and leave the business exposed if the project misses its target date after Microsoft support has ended.

Partner capacity may also become a consideration as the deadline approaches. Dynamics SL and Dynamics GP are both legacy Microsoft ERP products with approaching lifecycle milestones, and many organizations will be evaluating migrations to Business Central during the same period. Starting earlier gives you more time to work with a qualified partner that understands both the legacy system and the destination ERP.

Business Central is often the natural replacement for Dynamics SL, especially for organizations that want to stay within the Microsoft ecosystem. However, it is not the right answer for every organization. As a multi-platform ERP provider, Rand Group can help you evaluate whether Business Central or another ERP platform best fits your project accounting, reporting, integration, industry, and growth requirements.

For organizations that are a strong fit for Business Central, the platform answers many of these pressures directly. It delivers project, financial, and operational functionality in a cloud platform that updates automatically and connects natively with Microsoft 365. To see how the two systems line up across features, licensing, and user experience, our guide to understanding Dynamics SL and Business Central’s differences offers a side-by-side comparison.

What a successful SL migration looks like

A migration can feel daunting, especially if a previous attempt stalled, so it helps to see what the process looks like when it works. A leading oil and gas company came to Rand Group after its migration had stalled, unsure whether it could reach a modern ERP without further disruption. Working together, the team moved the company to Business Central and turned a stuck project into scalable success.

The results showed up in the numbers that matter to a finance team. Among other gains, the company achieved a 40% faster vendor remittance email process, freeing staff from manual work and speeding up a core accounting task. You can read the full story in our oil and gas migration case study.

How Rand Group helps you plan your next move

Whether you decide to optimize Dynamics SL today or begin your move to Business Central, having the right partner makes the difference between a smooth transition and a stalled one. Rand Group brings a proven migration methodology and a team of certified CPAs and industry specialists who understand both the technology and the finance and project workflows behind it.

Our 90% client retention rate also reflects our focus on building long-term relationships that continue through implementation, training, support, and ongoing system optimization.

Our team can support you at every stage of the journey:

• Legacy migration services: We assess your current environment and plan your move to Business Central with your data, customizations, integrations, reporting needs, and business processes in mind.
• Ongoing Microsoft support: After go-live, our support team helps resolve issues, maintain system performance, and identify opportunities for continued improvement.
• Dynamics 365 training: We provide role-based training designed around your processes so employees can use Business Central confidently and effectively.

Frequently asked questions

Planning your next step with Dynamics SL

Dynamics SL has served project-driven businesses well for decades, but its lifecycle is drawing to a close, and the teams that come out ahead are the ones that plan their next step early rather than waiting for the deadline to force their hand. Whether that means getting more value from SL in the near term or mapping a thoughtful move to Business Central, a clear plan protects both your operations and your data. When you are ready to talk it through, contact Rand Group and our experts will help you chart the right path forward.