Roadels: Discrete information objects for production planning and control of road construction

Road construction is fundamentally different to building construction, in terms of its products, the types of work and operations, and the resources used. One of the key differences from the point of view of planning and control of production flow is that roads are composed of geometrically continuous courses rather than discrete 'products', making work packaging difficult. Clearly defined work packages that comprise work performed on distinct products are central to lean construction methods of planning and control, such as the Last Planner System. We therefore propose a product schema which models road sections with distinct road course segments that are dynamically defined aggregations of 'roadels'. A roadel is a fine-grained vertical triangular prism object that can be dynamically aggregated with other roadels to represent a road course segment associated with a work package, a planned task, or an as-built section. The schema represents the continuous nature of road construction, and its discrete entities enable representation and computations of as-made work using the raw data obtained from machine-mounted sensors and land surveys. We describe the information schema and illustrate its use for computation and analysis of lean production flow metrics. The schema has been tested using case study data from a 25,000 m2 parking lot project, which was modeled with more than 560,000 roadels with as-made status data collected from 33 working days over a period of two months.