How We Converted an MS Access Application into a Full Web-Based ERP Solution

Introduction: From Legacy Access to Modern ERP

For more than 40 years, a leading chemical manufacturer ran daily operations on a massive MS Access application. Originally built 20 years ago, the system had become the backbone of the company—covering everything from inventory to accounting. In reality, it functioned as a full ERP solution, though it had never been called one.

Unfortunately, the application had not been maintained for years. Their former developer was no longer available, bugs piled up, and new business needs went unmet. This is where our expertise in C# development, custom software development and database design came into play. We took on the challenge of stabilizing the Access system, to convert MS Access database to SQL Server, and ultimately delivering a fully scalable web-based solution as an ERP.

Step 1: First Contact and 10-Step Engagement:

The journey began with a single email request for an MS Access developer. Rather than jumping directly into fixes, we asked the client to review our process, the first step we take to engage with the client during the initial phase of a custom software development project.
As part of this step, we shared our article: Custom Software Development – 10 Steps to Engage With the Client which outlines our proven process for ensuring alignment and clarity before development begins.

The client responded with an email that included detailed answers based on the guidelines in the article. These responses showed their commitment to investing the necessary time, which was essential for the success of this software development process.

In our first meeting, we discussed the following:

Their business rules in details
The time commitment required from their team
Expectations for meetings, reviews, and approvals

This structured approach helped us avoid wasted efforts and set a clear foundation for collaboration. We also learned that the company’s owner, a Ph.D. in Chemistry, and the controller would take part in the initial meetings. Their active participation gave the project strong direction from the start and created confidence in achieving the desired outcomes.

Step 2: Maintaining While Preparing for Migration:

The client couldn’t afford downtime. Before replacing the old system, we agreed to maintain and stabilize their MS Access application. Our team fixed bugs, ensured continuity, and learned the system’s workflows while simultaneously preparing for a modern solution. This double task strategy allowed us to keep operations running smoothly while planning the database migration, to convert MS Access database to SQL Server and begin building a scalable, web-based ERP through custom software development in C# and .NET.

Step 3: Comprehensive Feature Discovery:

We conducted a series of deep-dive meetings with stakeholders.

With the Owner: We explored operational features like inventory control, formula management, label creation, raw material tracking, warehouse management, quotes, purchase orders, and batch processing.
With the Controller: We reviewed financial features such as invoicing, accounts receivable, accounts payable, and raw material payments. We also examined how QuickBooks was integrated into their accounting workflows.

It was a large and complex MS Access application, yet no documentation existed to explain the database structure or database design. Multiple algorithms were embedded across different processes, but not a single note had been left behind. Our discovery sessions were essential to uncover these details and ensure nothing was missed before planning the migration.

Step 4: Reverse Engineering the MS Access Application:

Because the original developer was no longer available, we needed to reverse engineer the MS Access system from the ground up. No documentation existed to describe the database structure or design, and many processes were hidden in code.

We followed a methodical reverse-engineering approach: we examined relationships, exposed hidden objects, traced startup sequences, reviewed event code, and worked through query logic and table-to-query flows.

We investigated:

Proprietary algorithms embedded in formulas
Inventory and raw material management logic
Relationships between tables and data dependencies
Custom workflows and business logic embedded in forms and macros

This step-by-step approach allowed us to fully map the undocumented MS Access application.

Step 5: Migrating MS Access Database to SQL Server:

The next major milestone was to convert the MS Access database to SQL Server, also known as upsizing an MS Access database to MS SQL.

We carried out a structured migration plan:

Analyzed and mapped table structures, relationships, and keys to document the existing schema
Cleaned and normalized data to improve integrity and performance
Optimized the SQL Server database design for scalability and future modules
Reviewed and migrated MS Access queries and expressions into SQL
Created stored procedures and sync routines to manage data during transition

By migrating to MS SQL Server, we removed the limitations of MS Access, ensured a secure and scalable database design, and established a strong foundation for the next phase of custom software development, delivering a robust web-based ERP system.

Step 6: Specifications and Database Improvements:

We created high-level specifications for each ERP module, shared them with the client, and incorporated their feedback.

Key benefits of this step:

The client clearly understood planned features before development began.
We enhanced existing modules based on business rules.
We improved backend design beyond what MS Access Application could provide.

We followed a rigorous Software Requirements Specification (SRS) process: defining functionality, creating a data dictionary, modelling entity relationships, and specifying expected performance, security, and external interfaces. This collaborative step helped ensure the ERP system was tailored to the client’s real-world workflows.

Step 7: Agile Development with C# and .NET:

Using C Sharp or C# as part of the dot NET. framework, we applied our expertise in C Sharp Development and adopted an Agile development approach, grounded in proven SDLC - Software Development Life Cycle principles. This helped us increase quality, accelerate delivery, and reduce cost through structured iterations.

The function of the SDLC is to save time and money during the process of developing custom software while also ensuring top quality. Really, most software projects fall victim to the same series of mistakes.

We started with essential modules such as Suppliers and Customers.
We delivered working increments early, gathering client feedback at each stage.
We iteratively refined features to match unique business requirements.

By aligning with SDLC best practices, and using Agile as our methodology, we kept the client involved, minimized errors, and ensured efficient progress toward the final ERP solution.

Step 8: Consolidating Multiple Systems Into One Web Solution as ERP:

The client had been juggling several disconnected applications, including QuickBooks. We consolidated them into a single web-based ERP system. With seamless QuickBooks integration, we eliminated double data entry and gave the business a unified view of operations.

Step 9: Advanced Inventory and Warehouse Features

Inventory posed unique challenges for a chemical manufacturer. Our ERP modules accounted for:

Finished goods that had to leave the warehouse quickly.
Samples tracked and shipped to prospects or customers.
CRM integration, enabling sales teams to track samples and seamlessly convert a prospect into a customer.
Drop shipment chains where Customer A resold to Customer B, sometimes extending to five levels deep.

These features gave the client precise control over inventory, warehousing, and customer fulfilment.

ERP-Integrated Visual Warehouse Management

To extend the advanced inventory features, we introduced a visual warehouse management platform fully integrated with the ERP system. This solution provides a floor-plan style view of warehouse operations, delivering live visibility and automation for every movement of goods to streamline inventory control.

Real-time tracking of inventory across the warehouse
Location-specific details displayed on a visual floor plan
Color-coded indicators for quick status updates
Barcode scanner integration for automated updates and error reduction

Step 10: Delivering a Scalable ERP Solution

In the final phase, we transitioned the business from Access to a future-proof ERP system:

Backend powered by SQL Server - A secure, reliable, and scalable database foundation that eliminated the limitations of Access.
Web application built with C Sharp Development on the .NET framework - We used a commercial .NET framework, which provided a full suite of pre-built features before development began. This included advanced security controls that allowed us to manage access down to individual menu features. Implementing these capabilities out of the box saved months of development time and significantly reduced risks.
Agile process for continuous improvement - We engaged closely with the client in short iterations, reviewed deliverables regularly, and adapted quickly to feedback. This minimized mistakes, reduced rework, and ensured the ERP solution aligned perfectly with real business needs.

Results:

Business operations stabilized during transition.
Multiple applications consolidated into one ERP.
Scalable, secure architecture designed for decades of use.

If you’re facing the same challenges—or your software/app is outdated—and you want to upgrade to a cloud-based ERP, contact us. We’ll migrate your existing database, improve your system, and convert it into a secure, cloud-based web application.

In addition, if you’re dealing with complex customer tiers or drop shipping across levels, we can help. We’ll migrate your data, improve your system, and deliver a secure cloud-based web ERP that supports multilevel fulfilment.

Frequently Asked Questions

How long does it usually take to convert an MS Access application to a web-based ERP?

Project timelines depend on the complexity of your database and required features. A typical conversion and rebuild process, including migration to SQL Server, database design, and web ERP development, can take a few months. We start with an evaluation to provide a clear project schedule.

Will we lose any of our existing data during migration?

No. Our process ensures complete data preservation. We back up and validate your Access data, then migrate it safely to SQL Server with full integrity checks to make sure nothing is lost or corrupted.

Can you modernize only part of our MS Access system instead of rebuilding the whole thing?

Yes. We often start with critical modules first, then expand as needed. This phased approach helps reduce cost, minimize disruption, and deliver results faster while planning for full system modernization.

Do you offer ongoing support after the migration?

Absolutely. After deployment, we provide maintenance, optimization, and feature updates to ensure your new C#/.NET ERP system continues to perform at its best.

How secure will the new web-based system be?

By rebuilding your application in C# and .NET on SQL Server, we implement advanced security features like role-based access control, data encryption, and secure authentication. This ensures your ERP system meets modern security standards.

What kind of businesses benefit most from this service?

Companies that have outgrown their MS Access applications, especially manufacturers, distributors, and service-based organizations, benefit most. We specialize in helping businesses move from desktop-based systems to secure, cloud-ready ERP solutions.

How can we get started?

You can contact us for a free evaluation. We’ll review your existing MS Access database, discuss your requirements, and outline the steps to migrate it to SQL Server and rebuild it as a scalable web-based ERP system.