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CHAPTER 4 DEVELOPMENT WORK ON FEL-CAPP SYSTEM

4.3.3.4 Steel Order Planning Area

Steel Order design is a activity conducted in this planning area, but the area also contains information fed back from the sister company, concerning the steelmaking programme and the cast analysis. It is the most complicated area in the process planning system.

The FEL Melting Range and the Ingot Requirement are the main items to be developed in the design of a Steel Order. The melting range is the chemical composition to be achieved according to customer specifications or requirements, as well as the present capability of the steelmaking processes and cost of these; while the ingot requirement is the designation of ingot sizes and some relevant parameters to be achieved, of which cost factors are also important. Both melting range and ingot requirement are the responsibility of different specialists - metallurgist and forge planner. Metallurgists normally take decisions in this part of process plan designing process. The system must, therefore, be able to pass information across to the forge planners. So that, once the steel order design has been completed by the metallurgists, the forge planners are then able to carry out their part of overall process plan. The system is designed to stop a steel order being issued without the metallurgists having approved the section for which they are responsible.

Once the steel order has been passed to the steel melting shop, the steelmakers are required to present their steelmaking programme to FEL for approval. As soon as the ingots are cast, the cast analyses must be recorded in the database. Both the steelmaking programme and the cast analysis are then checked to see that they meet FEL's

CHAPTER 4 DEVELOPMENT WORK ON FEL-CAPP SYSTEM

Appendix 1-5 lists all the relations in this planning area. Among them, FSLJProc, FSL_Ingot, FSL_Programme constitute the Steelmaking Programme, and

Analysis_index and Analysis constitute the Cast Analysis, although neither is shown in Figure 4-5.

1. Steel Order and Ingot Requirements

As shown in Figure 4-5, the SO_Status, Steelord and FEL Melt. Range relations form one part of the steel order, and the relations - Ingot Requirement, Ingot Status and Ingot, form the other. Even if they come together into one process plan, we need to keep two status relations because they serve two different functions. The SO_Status (Steel Order Status) uses a single FEL Order Number format in each record, the Ingot Status uses a string for the group of forgings since a single ingot can be formed into more than one forging.

All these relations except the FEL Melt._Range relation, use the same field combination as the primary key to identify the relevant records. The FEL Melt. Range on the other hand is identified by its unique number, Melt._No., which is recorded in the Steelord relation.

2. Steelmaking Programme and Cast Analysis

Every works order that is required to be cast by the steel melting shop should have its corresponding steelmaking programme and cast analysis reported from the sister company, FSL. It is therefore necessary to add primary keys from both reports into the SO_Status relation for each single order number. Null value would occupy those fields in SO_Status, at the steel order designing stage. These values mean that no relevant report exists in the related files at that early stage of the forging manufacturing

CHAPTER 4 DEVELOPMENT WORK ON FEL-CAPP SYSTEM

sequence. When steelmaking is complete, those two numbers will be assigned to each works order in order to relate all the plans and reports together.

It is necessary to point out that the data manipulations within this area are dealt with in a similar fashion to data manipulation in other areas, i.e. data operations take place on records created in temporary facsimile files before entering those records into the database and issuing them for execution.

Constructing a melting range is one of the major tasks in the steel order design. It requires expert knowledge and experience. The system is designed to assist the experts in tracing a satisfactory melting range quickly and consistently, or to design a new one based on certain constraints. The intention in designing the database is to improve the standardisation of melting ranges and to provide a rational way to modify and extend the melting ranges in use. This will be examined in detail in section 4.6 to show how the system assists in the design of melting ranges.

4.4 Quality Assurance Functions

Quality assurance tasks are considered, at FEL, to be the prime concern that underlines all activities from the start of a contract order, through all the processing steps up to finish and delivery; ensuring that the correct methods and techniques have been used at all stages and that they conform to the required standards. The following tasks have been identified and incorporated into the current database system.

1. Updating specifications;

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3. The feeding-back information such as melting programs and ingot analysis, etc. The selection of these tasks is controlled through the menu system developed as shown in Figure 4-11.

4.4.1 Integration of Quality Assurance Functions

Apart from specifications which already exist in the database to support metallurgical functions, the other QA aspects have not been described. In this section, we first discuss how the QA function is applied to the control of specification withdrawal, and then move our attention to organising and maintaining the issue status of process plans and automating the approval and acceptance mechanisms for melting programmes and ingot analysis.

4.4.1.1 Specification Control

The specifications are actually stored in the current database and entered by

metallurgists in the forging definition database planning area (see Fig. 4-5). Their data structure has been described in the section 4.3.3.1 dealing with Forging Definition Planning Area. This section will show how quality assurance functions are incorporated by modifying relations already described.

According to the company's ASME Quality Manual for the control of the steel specifications, previous issues of a specification should be withdrawn once a new version is issued. In a manual system, hard (paper) copies of a specification can be

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QUALITY ASSURANCE FUNCTIONS