Bridge inspection operations involve a wide range of data tied to spatial coordinates, including the physical location of inspected members, defect points such as cracks, and inspection photos. Although this data is centrally managed in inspection systems and GIS (geographic information systems) operated by local governments and road operators, differences in geodetic systems or coordinate formats depending on the input source—such as global geodetic systems, plane rectangular coordinate systems, or member-local coordinates—often led field engineers and office staff to perform manual recalculations and data transcription.

In particular, because coordinate conversion logic had been implemented separately for each business function, calculation errors and inconsistencies in location information occurred between systems. This increased the effort required for verification and the cost of rework. To improve the efficiency of future inspection operations, it became urgent to build a secure, error-free data integration mechanism while making use of the existing business platform.

The purpose of this project is to provide a mechanism that can accurately and reliably convert and share various coordinate data and inspection records related to bridge inspections within the client’s existing core system.

Rather than rebuilding or replacing the system from scratch, we made full use of the inspection workflows refined over many years and the existing software assets. Our goal was to automate data integration while ensuring location accuracy, without significantly changing the user experience in the field.

SMILE handled the entire process, from converting the core coordinate transformation engine into a library to designing and implementing the inspection data sharing API, conducting integration testing with the existing system, and providing maintenance support after production launch. The main scope of work was as follows.

• Implementing algorithms for a shared library that handles spatial geodetic systems and coordinate conversion (C# / .NET)
• Developing a data-sharing API that seamlessly passes inspection records and component information to other functions
• Adjusting interfaces with the current system’s UI layer and existing data structures
• Accuracy Verification Based on Real-World Operational Scenarios Using Survey and Inspection Data
• Performed regression testing and optimized rendering and computational workloads
• Post-release defect investigation, performance monitoring, and ongoing maintenance support

The primary focus of development was designing the coordinate conversion process as an independent shared library (DLL). Rather than embedding the conversion logic within a specific screen or function, we externalized it as a shared component with loose coupling, ensuring the extensibility needed for reuse in future feature enhancements and integrations with other systems.

To reduce the workload on field personnel, SMILE implemented UI integration based on a design principle that keeps the transformation process invisible to users. Users can simply register and view inspection data as usual on the familiar existing screens, while accurate coordinate transformation and data integration are completed automatically in the background.

Because infrastructure inspection data directly affects structural health assessments, SMILE went beyond standalone calculation tests and repeatedly performed integration verification using production-equivalent data from the existing system. This eliminated rounding errors and boundary-value defects in the data.

The greatest technical challenge was processing multi-stage transformations at high speed while maintaining millimeter-level accuracy, from different geodetic systems such as global GPS coordinates and latitude/longitude to the plane rectangular coordinate system used in Japan’s public surveying, and further to local member coordinates for bridge structures. With the legacy process, accumulated rounding errors and differing interpretations of coordinate systems could occasionally cause positional deviations, creating a risk of hindering accurate identification of inspection locations.

SMILE rigorously coded transformation logic compliant with Japan’s Ministry of Land, Infrastructure, Transport and Tourism standards and geodetic surveying specifications, and validated it using an extensive set of boundary-value test cases. We also optimized memory usage and improved algorithm efficiency to account for the load generated when processing large volumes of inspection points in batches. As a result, the system delivers highly accurate transformation results instantly without placing excessive demand on existing server resources.

By fully automating coordinate transformation and data sharing, the project eliminated the manual calculations and duplicate data entry previously performed by field engineers and administrative staff.

Location information for inspection points can now be managed consistently across multiple systems, creating an environment in which past inspection histories and the progression of damaged or deteriorated areas can be tracked and compared accurately. This has made a major contribution to eliminating human error and significantly reducing lead times for preparing inspection reports and performing data analysis.

In this project, the specification contact on the Japan side worked closely with the development team in Vietnam to establish a framework that prevented misunderstandings around business rules and geodetic surveying terminology specific to infrastructure inspection in Japan. The Bridge SE (BrSE) clearly interpreted and communicated the definitions of geodetic systems and the data specifications of the existing system to the development team, ensuring a shared understanding throughout the project.

For areas requiring especially high calculation accuracy, we worked with the Japan-side team to define a test matrix specifying input data and expected results, building quality into the solution through test-driven development from an early stage. By taking advantage of offshore development to run rapid verification and improvement cycles, we delivered a highly accurate solution on schedule.

This case study highlights a successful implementation in bridge inspection, a highly specialized area of infrastructure management, where precise, high-accuracy technical components for coordinate conversion and data sharing were integrated into the existing system. It demonstrated that even without a large-scale system overhaul, modernizing the data integration layer that had become a bottleneck can dramatically improve both operational efficiency and data accuracy.

SMILE supports customers’ DX initiatives in the development and integration of GIS and surveying data processing systems, as well as infrastructure inspection business systems, by combining deep operational expertise with proven algorithm implementation capabilities.