Formal Methods and Standards - An Idiosyncratic View

Many of the reported experiences in the industrial use of formal methods concern the development of products or product families, where the utility of the method is linked to direct savings in development costs or improved assurance of quality. However, one other area in which formal description techniques make a valuable contribution is in the development and documentation of International Standards, where the cost of using formal methods can be paid off both through increased quality of products that implement a given standard, and through the improved inter-operability of different implementations that comes from having a precise definition of the expected behaviour of a conforming implementation. The process of standardization within ISO/IEC is complex, and affords the oppertunity to use formal methods at different stages and in different ways. This paper illustrates how formal methods have been used in the development of two standards, the computer graphics standard, GKS, and the multi-media standard, PREMO. Formal methods have been used at different points during their development. This paper concludes with an appraisial of the work done and some thoughts about future directions.