ABSTRACT: The Mine Project Planning System (MPPS) began development at the Institute of Mining and Metallurgy Machinery of Aachen University of Technology in 1992. Against a background of large data quantities, long term planning and many complex inter-dependencies between planning factors, MPPS offers an especially important source of assistance for the detailed cost related planning of mining operations. The different mine planning tasks are handled by the various MPPS modules which access a common (relational) database. The system has been realized in close cooperation with Ruhrkohle Bergbau AG (RBAG).

    1 INTRODUCTION

   Production planning in German hard-coal mines depends to an especially high degree on the existing conditions of the mineral deposit. The expense in terms of capital and resources is considerable, and because of the long distances involved between the different parts of the mineral deposit start up times are large. This fact leads to the wide planning horizons of the production work and their consequent high risks. For this reason, the planer naturally wants to receive accurate information concerning the mining operation, together with immediate and reliable evaluations of the different available production plan alternatives.

   1.1 Need for a new system

   To support the production planning and controlling activities, the Ruhrkohle Bergbau AG (RBAG) installed a number of computer based applications in the early seventies and has expended these applications into a single central planning and information system. But these mainframe-based applications cannot meet the rising demand on information processing regarding the analysis, access, exchange and management of data. So the RBAG was faced with the task of transforming its centralised working system into a modern information system with decentralized structures. To achieve a part of this aim, the RWTH Aachen, in cooperation with the RBAG, has developed a new planning and information system for mine project planning in the hard coal mining industry; namely the Mine Project Planning System (MPPS).

   2 PROJECT PLANS STRUCTTURE

   The project plan structure used by the MPPS utilizes that set down by the RBAG. All activities are named and ordered according to the guidelines for the internal working point posting.

   According to these guidelines, the underground area is divided into different accounts between which all costs are distributed. The accounts are defined as six-figure numbers, describing working point and activity. The working points can also be thought of as cost centres and the activities as cost objectives.

    Figure 1: Project structure and gannt chart

   Figure 1 shows an example of the accounting system in connection with a gantt chart, and illustrates the lifecycle of panel 502. The working point descriptors face 5028, bottom road 5020 and the top road 5021 build the first four-digit part of the key. The activities advance (5020 10), hauling (5020 24) etc, are described by the last two digits. For a complete description of an underground activity two additional digits are required. The production rate, for example, charges as the panel is progressively mined. At the beginning and the end of the extraction activity a lower rate will be expected and planned. Therefore the activity is divided into different parts, each identified by two digits. Taking our example of the extraction activities, the initial activity could be described with the key (5020 22 10), the regular extracting activity with (5020 22 20) and the end with (5020 22 30). The resulting eight- digit key is called a sub-activity and represents the highest degree of detail in the project plan.

   3 GENERAL STRUCTURE OF MPPS

   The heard of the system is the ORACLE7 relational database. It is designed as an open system, easily expandable to meet future demands. One main focus of the design has been the data integrity, which is guaranteed by extensive consistency checks (using ORACLE constraints). This allows standard applications to access data safely.

   Built on the MPPS-database, an application system has been developed that fulfils the special requests of mine planning and supervisory activities, and also covers the functions of cost and result analysis in the production planning at the RB AG.

   The MPPS-application system has a modular structure. It consists of the modules Master Data, Administration, Configuration, Time Scheduling (also "Plus 1"), Analyzer, Actual Data and GRUBE-B. Each module is accessed through a graphical interface, (implemented with OSF/Motif and additional third party widgets), and each accesses the MPPS-database. Figure 2 show the structure of MPPS and its environment.

    Figure 2: Structure and environment of the MPPS

   4 MPPS MODULES

   4.1 Module Master Data

   The module Master Data is the central 'frontend system' for the manipulation of project data. Using this application the planning of the project structure (including the order in which processes will be carried out), cost and resources can be carried out.

   In term of project planning, the module Master Data supports mainly the definition and administration of plans.

   Master Data has a number of editors, which are all started from the main dialog. The following objects can be edited by these editors: project descriptions, working points, master data for excavation, advance, drawing off, equipping, demounting and other activities, costs, order connections, cost objective assignments and user-defined data. All editors can work simultaneously and changes made in one editor are reflected straightaway in all active editors.

   Figure 3 shows the editor for the excavation master data. White input fields can be edited. The upper part of the editor contains information about the lower part of the editor the activity data is displayed. The fields with the arrow-buttons show activity mine dependent data such as support. By activating an arrow button, a user can select from a list of predefined values. Beside standard operations like "Save" or "New", the operation of assigning formulars under "Settings" should be mentioned. Derived values (ie. those dependent on a number of other factors) such as production rate can be assigned different formulars, according to which of the dependent factors should be updated if the derived value itself is changed. Dependencies are then recalculated according to the chosen formular.

    Figure 3: Master data editor

   4.2 Module Configuration

   The Configuration module is used for updating general mine data and supports mainly project preparation. From the main dialog, the desired class editor can be popped up. Information belonging to the following classes can be edited: panels, seams, sorting characteristics (face advancing, goaf treatment, crew-name, exploitation method, driving method), equipment categories, and support.

   4.3 Module Time Scheduling

   The Time Scheduling module is a commercial project management system and has been integrated into the MPPS. The program, 'Plus 1', was purchased from the company ACOD GmbH, Munich. This software performs the required project time scheduling and generates reports in the from of bar plans, gantt charts, critical path diagrams, curves of cost resource data etc. the main task of Plus 1 in the MPPS is the generation of excavation plans, crew plans and project plans.

   The time scheduling in Plus 1 utilises the Precedence Diagram Method and prossesses a remarkably fast algorithm. Before a calculation, Plus 1 reads all relevant project data from the database and stores it in the computer's main memory for rapid access.

   The result of a time scheduling can be saved in the database or checked (and changed) directly in a bar chart editor (Figure 4).

    Figure 4: Bar chart editor in Plus 1

   4.4 Module Administration

   The module Administration gives on the one hand the possibility of enlarging the database with new user defined tables. On the other hand, interfaces to other external programs and external data sources can be configured. These are namely the interface to Plus 1 data and interface to plan data generated by existing mine planning systems.

   4.5 Module Analyser

   With the module Analyser the user is able to define database queries, and to make comparisons between different projects or between target and actual situations. Therefore this module supports mainly supervisory tasks and cost and resource analysis. It is also possible to use standard applications like Microsoft Excel or Oracle Forms to perform project analyses using the MPPS database.

   4.6 Module Actual Data

   The development of this module is currently in progress; this module will be used to capture the actual state of mining activities. An interface to the actual data resource is planned.

   4.7 Module GRUBE-E

   This module currently only exists as a prototype. It handles the connection to the GRUBE-system that has also been developed at our institute in Aachen. With GRUBE-E the geological and especially the survey data external to the MPPS can be analysed. All aspects concerning the simulation of the operating activities will also be covered.

   5 FIRST RESULTS AND OUTLOOK

   First experiences with different mines and central departments of the RBAG have show that with MPPS a promising path towards the improvement of mine project planning has been followed and one large step in the direction of a global, transparent and flexible information system has been made. Complete project consisting of both existing data (imported using MPPS) and directly entered data, have been mapped and analysed with MPPS. Queries to the database have been made on a PC with MS Excel or better MS Query in a heterogenous network with an IBM RISC Workstation acting as the central database server. Outputs in the form of bar charts have been printed. Other outputs in the form of lists will be generated with the standard software Business Objects for Excel.

   6 CONCLUSIONS

   Some issues related to the design and realisations of MPPS have been addressed. The system has been developed by the Institute of Mining and Metallurgy Machinery of the Aachen University of Technology in close cooperation with the Ruhrkohle Bergbau AG. It assists the planer in different areas such as time scheduling with the help of activity networks, cost and resource planning, analysis of prognoses, plan and report generation etc.

   The project structure which is mapped in the system follows the guidelines for the internal working point posting of the RBAG. Any mining activity is described as sub- activity identified by an eight-digit number. Cost planning by the assignment of cost data to cost centres is possible. The cost data can be further broken down into the various cost categories.

   The different tasks are taken care of by several modules which access a common ORACLE 7 relational database. MPPS is a multi-platform, multi-user system, and runs on RISC workstations and PC's (under UNIX). Except for the commercial time scheduling module Plus 1 all user interfaces have been implemented with the OSF/Motif widget library and separately purchased third party widgets.

   First experiences using MPPS on mines and central departments of the RBAG have been positive. Project planning with MPPS, data exchange between former planning system, standard query tools, and report generators satisfy most of the needs of the RBAG.