In an object oriented computer system, one or more run-time extensible items are defined that may be dynamically reconfigured as required to support different interfaces at run-time. Also disclosed is a system and method for using such employee-specific and service location-specific data to produce numerical measurements of quality, and to convert those measurements to points that may be exchanged for rewards, incentivizing good service and participation in the quality control system. Each of the connection shafts is connected to a table top so that the two table tops are pivotable about the shaft as desired. When collars are placed into the last two or three grooves on each end of a grooved roller, a non-shouldered grooved roller is thereby converted into a shouldered grooved roller without having to remove and replace one set of rollers with another. The scene change determination module determines that a scene change is occurred between two image frames when an amount of change between the outlines in the two image frames exceeds a prescribed threshold value. The absorber allows more precise adjustment of tightness and helps prevent accidents caused by over-tightening of tarps or by tarps loosening during load settling.