Built a multi-tenant construction ERP platform with mobile and desktop integration

123 Works provides construction businesses with a centralised ERP solution for managing workforce operations, timesheets, expenses, payroll, and subcontractors — delivered as a multi-tenant SaaS platform.

Their goal was to replace disconnected manual processes across multiple construction enterprises with a single, scalable system — accessible on web and mobile, and integrated with their existing Windows desktop tools.

• Weekly and monthly timesheets managed manually, creating delays and errors across payroll cycles
• Expense and mileage reimbursements tracked through disconnected, error-prone processes
• Leave requests and approvals handled across separate systems with no centralised visibility
• Subcontractor work tracking lacked structure and real-time oversight
• No centralised data layer to support multiple enterprises within a single platform

1. Understand construction workflows before designing the system

We ran detailed stakeholder discussions to map how construction businesses manage timesheets, payroll cycles, and subcontractor work — ensuring the platform reflected real operational logic, not generic ERP assumptions.

2. Architect for multi-tenancy from the start

The platform needed to serve multiple enterprises independently within one system. We designed secure data segregation and a scalable multi-tenant architecture before any development began.

3. Build modular, function-by-function

Each business process — timesheets, payroll, expenses, leave, subcontractors, GRN — was developed as a self-contained module, allowing independent configuration per enterprise and cleaner future extensibility.

4. Integrate with what already exists

Rather than replacing the client's Windows application, we built REST APIs to export timesheet and expense data directly into it — preserving existing workflows while adding new platform capability.

Core ERP Modules

• Monthly and weekly timesheet management for different employee pay cycles
• Employee expense tracking and mileage reimbursement management
• Leave application, approval workflows, and balance tracking
• Automated payroll processing with cycle-based calculations
• Subcontractor work tracking with Jspreadsheet-based data management
• Goods Received Note (GRN) recording and management

Platform & Integration

• Multi-tenant SaaS architecture with enterprise-level data segregation
• REST APIs for timesheet and expense data export
• Integration with client's existing Windows desktop application
• Responsive web interface built on PHP, MySQL, and Bootstrap

Mobile Application

• Cross-platform iOS and Android app built in React Native
• Mobile access to timesheets, expenses, and approvals for field staff and managers

Construction enterprises using 123 Works moved from manual, disconnected processes to a single platform managing their entire workforce operation — with payroll, expenses, leave, and subcontractor tracking all centralised and accessible on web and mobile.

Business Impact

• Reduced manual effort across timesheet entry and payroll processing
• Improved accuracy of expense and mileage reimbursement calculations
• Streamlined leave and subcontractor workflows across multiple enterprises
• Seamless data continuity with existing Windows applications via REST APIs
• Mobile access extended platform reach to field staff and on-site managers