2.3 Procedure at Plan Approval
The discussion in this section is concerned with how the work of plan approval is affected by the use of EDI. A rough outline of the plan approval procedure as currently practiced is described below.
1. Work associated with the plan approval process at the propeller manufacturer
An outline of these tasks is as follows:
(a) Preparation of the document for the performance of calculations.
(b) Preparation of the document for the conduct of strength calculations.
(c) Preparation of the drawings.
(d) Preparation of the necessary number of copies of the above documents.
(e) Preparation of the application sheet for approval.
(f) Sending of the above documents via the branch office to the head office of the classification society by mail.
Fig.1 shows the relation between the propeller design database and various systems to assist the design work. As can be seen in Fig.1, the propeller design database is the core to which each system is connected. However, not all items necessary for the work of the approval are stored in the propeller design database because the output is almost always in the form of a paper document.
2. Work associated with the plan approval process at the classification society
An outline of these tasks is as follows:
・Determine compatibility with the Rules
・Examination by strength calculation
・Input of data into a database
As can be seen from the above description, the database (which is referred to as the machinery particulars database: stores various particulars of the machinery equipment examined by the classification society) and the strength calculation are used when the plan approval work is carried out. Fig.2 shows the loose connection between the machinery particulars database and the strength calculation which is used to determine the compatibility of the design data of the propeller. The interface for the data input installed into the client machine is done using an Excel spreadsheet and has a button to call the strength calculation.
Of course data entry is carried out more than once during the process described above.
If EDI is put into practice, the procedure of the plan approval will become as follows.
1. Work associated with the plan approval process at the propeller manufacturer
As mentioned before, the current system for the design of the propeller is built on the assumption that the form in which the data is the be processed is a paper document. Therefore, a database to store the data for approval becomes necessary as shown in Fig.3. In the case of the strength calculation, for example, the data of the design condition is stored in the propeller design database and the results of the calculations are stored in the approval database, respectively. When the approval is carried out, the necessary data is retrieved from each respective database and transmitted.
2. Work associated with the plan approval process at the classification society
The scenario outlined above seems to be nearly same as one currently in use except for the transmission of data via the network. However, there is a major difference between the processes two before and after the data is transmitted. For example, Fig. 4 shows an outline of the work of the approval process at the classification society after EDI is realized[1]. This framework consists of three modules, that is the "Regulation Auto-Check System", the machinery particulars database and the strength calculation. The "Regulation Auto-Check System" is an expert system which is designed to carry out the plan approval task automatically[2]. The data transmitted via the network is stored into the machinery particulars database and a portion of this data is used in the "Regulation Auto-Check System". After the data has been received by the classification society, following two scenarios can be considered.
(a) First way of use
The staff in charge of the plan approval process executes the strength calculation program linked with the input module for the machinery particulars database. When the strength calculation program needs data which is already stored in the machinery particulars database, the data is sent to the strength calculation during execution. Conversely, data generated during the execution of the strength calculation is sent back to the machinery particulars database, if necessary.
(b) Second way of use
When the staff in charge of the plan approval process activates the "Regulation Auto-Chock System", the data necessary for the system will be retrieved from the machinery particulars database, If the data stored in the machinery particulars database is insufficient, the "Regulation Auto-Check System" system prompts the user to input the required data The calculation necessary for "Regulation Auto-Check System" is performed by calling the corresponding strength calculation program.
3 Data Description using XML
A description of the propeller data using XML is explained in this section.
3.1 Outline of XML
XML is a subset of SGML (Standard Generalized Markup Language). Many functions of SGML are simplified and removed while functions necessary for network use are added.
