Logistics functions directly support the principal operation. In the international petroleum industry they mainly are maintenance, materials and transport. CALM is a microcomputer system which integrates the arrangement of these functions. It operates at the plant level. There are six CALM subsystems: 1) equipment control; 2) maintenance work control; 3) materials control; 4) transport control; 5) budgeting and costs and 6) management reporting. CALM is a collection of relational data bases and application programs. Its modules are distributed and are under user control. Data bases are designed for three organizational levels: 1) local area networks on microcomputers at the user level (CALM ); 2) relational data bases on minicomputers at the plant level and 3) relational data bases on main frame computers at the corporate level. This is said to be a 3-level computer system. Data base design is optimized over the three levels. System integration requires strict discipline over the design of identification codes (equipment, spare parts, job plans, job orders, failure reports, etc.). The paper suggests standard code formats which have proved to be successful in industry. Besides CALM, integrated systems from four multinational oil companies are discussed. Design errors experienced in these projects are described. Specific design precautions are emphasized. |