The cost of the former continues to decline because of the progress being made in the development and use of Information Technology (IT) techniques which have since become the standard environment for the creation and execution of software applications. In the case of FEM (Finite Element Method), for example, expensive solvers had been used before on large main frame computers. FEM calculation systems can now be operated using the graphical user interface on personal computers. On the other hand, costs associated with the generation of data are increasing more and more because of the areas which form the target of the data processing application are continually expanding along with the various kinds of data that have become necessary. In the case of the FEM calculations mentioned above, the costs involved in generating the model constitute almost the entire cost of the process.
One means of reducing the cost of data generation is to use a system in which data is generated automatically instead of manually. However, this is not a simple task except in cases where the data necessary for the application can be defined clearly, that is, in a very well defined manner. Whatever method is used, however, the data still needs to be generated. Hence, the most realistic way to keep the cost of data generation low is to generate the data only once. This can be realized by exchanging data via electronic data interchange (i.e., EDI) among the various applications being used. It is necessary for the efficient data transmission to integrate the concerned applications. Utilization of a network is also indispensable for this integration.
Before the Internet became available, it was difficult and expensive to create an integrated environment for a data processing system that also included a network infrastructure. In spite of this, however, it did become possible for data to be shared within an organization using some relatively convenient methods. Still, the transmission of data beyond the organization, that is to say, EDI, remained so difficult that it was not practical except for only a few major organizations. It would be natural under such circumstances that electronic data was generated in each instance where the data was necessary. Even further, the generation of data at more than one location encountered problems not only in terms of cost but also in terms of the accuracy and consistency of the data. Therefore, it has become natural to use intranet technology, derived from Internet technology, which is accordingly low in cost to use.
2.2 EDI of the propeller data
Now we start to discuss the main theme in this paper. Generally, cooperation between proper organizations is necessary for any experiment of EDI to be carried out effectively. This situation must need the proper cost and time. The aim of this research is to gain some idea of what will be required for a large-scale experiment which will be carried out in near future. To do so, we are now carrying out a small-scaled experiment under the following restricted conditions.
1. Consider EDI between the classification society and the manufacturer of the equipment for a ship.
2. The target of EDI in this case is concerned with the design data of the propeller.
3. The object of this experiment is restricted to data transmission for plan approval from the propeller manufacturer to the classification society. The return of the approval result is excluded from this experiment.
4. XML is used as the format to describe the data to be transmitted.
The first condition is merely due to the fortunate coincidence that both authors belong to the classification society and the propeller manufacturer, respectively The object of EDI between the classification society and the manufacturer is the transfer of data regarding the design and strength calculations necessary for the plan approval by the classification society. The period of EDI between these two organizations is relatively short through the whole life-cycle of the product. Hence, this type of EDI will be not difficult because the data to be exchanged can be determined clearly.
The second condition is due to the fact that one of the authors belongs to the propeller manufacturer. Moreover, the data of the propeller can be processed easily because it has little connection with other marine equipment and there is little need to refer any other data except that for the propeller itself.
The third condition is due to the fact that the volume of design data to be transmitted at the initial stage is relatively large in terms of both quality and quantity among the data interchanged between the two organizations. Therefore, the effectiveness of reducing costs is relatively high from the viewpoint of the maintenance of data accuracy.
Though it is not really necessary to refer to the fourth condition at this moment, it is mentioned briefly here because of its importance. The most difficult problem regarding EDI is determining what data format ought to be used, as mentioned before. The data to be interchanged is usually consists of the input or output of some application such as a CAD system, a word processor, or the like. The data format is special to each application in most cases. This problem does not cause major trouble by standardizing the application in cases where the area of EDI is restricted to one organization. However, data transmission between different kinds of applications, such as between a CAD system and word processor, cannot be carried out easily. In this situation, XML is gaining a lot of attention. XML can be considered as being a data description language in the same sense that C, FORTRAN and COBOL are program description languages. However, it is obvious that the situation is not improved at all if XML is used in only one organization. Fortunately, the following trends are taking place with respect to the use of XML.
・It begins to prepare the interface between XML and the application such as those for office use or DBMS.
・The tools to process XML are being supplied at low prices (free in some cases).
These trends are making it easier for small-scaled organizations to utilize XML.
