Examples of vertical integration within the "Irving Group of Companies" (as the Irving family refers to their holdings) include the acquisition or formation of businesses along the entire chain of production, from the Irving refinery (an Irving Oil subsidiary) and its retail outlets, to the transportation subsidiaries of J.D. Irving (RST, Midland, NB Southern, Sunbury), to various construction and engineering companies that assist in building, maintaining and expanding the conglomerate's facilities. Further examples of vertical integration within the conglomerate include Industrial Security Ltd. (ISL), the wholly owned security company that guards facilities, as well as industrial suppliers such as Thornes, Universal Sales and Commercial Equipment Ltd. which provide specialty goods and services to its companies.