DEVELOPMENT OF AN INTERNATIONAL STANDARD FOR DOCUMENTATION OF SOFTWARE FOR PROCESS MEASUREMENT AND CONTROL-SYSTEMS AND FACILITIES

Managing documentation of the control system, especially its software portion, is a major challenge with a direct impact on the cost and sch edule of implementation. As the design progresses, the hardware part o f the documentation generally becomes fixed in a manner similar to con ventional control systems. The software part of the documentation is m uch less stable. It goes through major changes during factory and plan t tests, and is continuously modified during plant operation. Existing documentation of software for process measurement and control systems is generally not satisfactory to the end user. A similar situation ex ists with other control facilities such as electrical transmission net works. Deficient documentation may result in millions of dollars of wa ste per project for the end user. Development of international standar ds in this area is considered an urgent need with the potential for ma jor impact on industrial process computer control system users and sup pliers. The International Electrotechnical Commission's Technical Comm ittee IEC/TC65 deals with standards for process measurement and contro l systems. A recently organized working group, WG7, has two years to c ome up with the draft of a standard ''Documentation of Software for Pr ocess Measurement and Control Systems and Facilities''. This paper pre sents the current status of this standard, which will eventually becom e a guideline for control system users and suppliers. The author furth er introduces some concepts on software documentation, which, in his v iew, simplify the process control system design management with time a nd money savings. The author intends to pursue these concepts in the f urther development of the subject standard.