抄録
Railway systems use computers in various fields. Software development for these systems requires not only a high level of safety, but also swiftness. One method of developing software is software prototyping. Prototyping can prevent discrepancies arising in the interpretation of system specifications among stakeholders, so that users' needs are more closely reflected in the specifications. On the other hand, computer systems need software updates. While updating software, the data to be updated needs to be loaded into the computer system. To achieve this, we are developing an Online Loading System. Although prototyping is usually applied at the stage of defining requirements, in this study we applied prototyping at the stage of examining specifications by a client, and we verified the effect of the prototyping by using it in the development of the Online Loading System. The Online Loading System consists of a Loading Management Device, Device A, and Devices B with eight functions. Digital prototyping using Microsoft Excel was employed as a user interface of the Loading Management Device. Six functions were used as targets for the prototyping because these functions are implemented via operations executed on the Loading Management Device. which has a user interface for an operator. In order to verify the effect of the prototyping, we investigated the analysis results of reviewing the prototyping for all six functions. In terms of revision categories, the number of revised items with the category "addition" was the largest, accounting for 60% of the total items. The second most common revised items had the category "change", accounting for 31%. There were few items with the category "delete", accounting for only 9%. This result shows that the prototyping is particularly useful for finding omissions in the specification. We also demonstrated that most of the items revised in the prototyping were found in the initial stage of reviewing.
