Hitachi Laboratory was one of the early exploratory users of ES technology. The Nuclear Research Laboratory sent two scientists to the United States to study the technology in 1981. Hitachi was the first to use fuzzy logic in a major application, the control of braking systems in passenger trains (Yasunobu and Miyamoto 1985). In 1982 the Information Systems Division also became interested in expert systems. Hitachi system engineers began to build many expert systems for internal use as well as for customer use. To date, there are about 100 systems developed for internal use, and more than 300 systems for Hitachi customers (for example, see Hitachi 1991 brochure, in English).
Hitachi has a broad range of ES products on the market: (1) the popular general purpose ES/KERNEL series; (2) task-specific tools in the areas of diagnostic and planning and scheduling applications; (3) the knowledge acquisition tool ES/TOOL/W-RI which can generate rules inductively from examples; (4) user interface-building tools (UIBT); and (5) an ES building support tool that guides the builder in an ES development methodology based on the spiral model.
In addition, Hitachi possesses the EUREKA series tools developed by the Heavy Industry Division for building real-time process control applications. Within this series is a more specialized tool called APOS for building advanced plant operation systems. APOS is built on top of EUREKA. Interestingly, ES/KERNEL2 also claims to be a good tool for building real-time control systems. It has been used successfully to build an expert system to control the operations of another blast furnace (Tano, Masui et al. 1988).
Hitachi claims that the demand for scheduling applications is overtaking the demand for diagnostic and banking/financial applications. Within the task domain of planning and scheduling, job shop scheduling is currently the biggest market, accounting for 40 to 50 percent of the scheduling business, followed by process scheduling. Demand for this class of applications began about three years ago. Based on its experience in building applications in this area, Hitachi has classified scheduling problems into four classes, and has developed techniques to solve each one. The company built and now markets a planning/scheduling tool called ES/PROMOTE/PLAN.
Hitachi was the first company to offer an ES tool written in C, and the first to offer one for UNIX workstations. ES/KERNEL/W, a workstation version of ES/KERNEL, is currently the best-selling tool, with more than 4000 copies sold in the last two years to 1,000 different customers. Notably, fuzzy logic is available as a part of ES/KERNEL.
At Hitachi, research is rapidly converted into products. One product under development, EXCEEDS 3, is for qualitative reasoning. Hitachi is also working on making ATMS (Assumption-based Truth Maintenance System) and case-based reasoning available in ES/KERNEL2.
Hitachi Europe, a small division of about 15 people, is helping in the development of ES/KERNEL2, which will be marketed by Hewlett-Packard in Europe as ObjectIQ. Hitachi Europe has also been working with a British firm, LOGICA, and the University of Edinburgh to develop an alternative to rule-based techniques for building scheduling systems. Called WHISPA, the program is able to generate schedules that perform one to two orders of magnitude faster in test cases. WHISPA has since been renamed ES/PROMOTE2/W-PLAN, and was released in August 1992.