Only a few years ago, there were questions over the benefits of distributed-processor-supported plant management systems. Now making savings in maintenance procedures is increasingly important to operators in the fiercely competitive energy market. Simple data-processing tools are giving way to systems providing information about the current state of the plant, as well as statistic evaluations based on structured data on the life cycle of plant activities and components.

Such a comprehensive plant management system has three objectives:

•To provide up-to-date information in the required form — particularly for planning personnel, who spend most of their time gathering information.

•To act as a workflow system, supporting work procedures for and in between operation, maintenance, technical modification and warehousing tasks. This shortens the execution times for these procedures and improves the quality of the work. The data obtained can also be employed effectively to improve both the process and the strategies used.

•To improve communication. For example, little time is required to transmit information in conjunction with work procedures.

Siemens KWU developed the application software system BFS++ (from the German word BetriebsFhrungsSystem, coded in C++) to support cost- and quality-optimised management in all types of power plant. The focus is placed on the support of technical organisational tasks, because money can only be saved where it is spent.

BFS++ covers the requirements of all technical fields in the power plant. It can be linked to existing computer systems, and this allows continuous work processes to cover business administration as well as technical fields, so technical staff can observe budgets and accrue costs online. Special emphasis was placed on the database because the data structure forms the basis for an efficient, future-oriented system. It should not be forgotten that most of the data will retain their validity for the entire life of the plant.

BFS++’s main benefit is in sup-porting efficient co-operation: it is used by all plant staff from worker up to the plant manager, offering a single system for all levels, organisational units and technical fields. Data are entered only once for everyone and everybody has access to the same data. Individual evaluations are possible for different areas and activities in the required form. If a task is executed by several groups, they communicate via a network or a common database.

The BFS++ system

BFS++ has a modular structure: it can be installed step-by-step and individual functions of the system can be selected for use. The following modules are available.

The plant database offers the building blocks for maintenance procedures. The scope and depth of its descriptions can be selected to match specific requirements. Any power plant identification system can be used to describe the tasks within the process, and it is possible to use more than one identification system within a single plant. All associated information (eg plain text, mounting location, design data, settings) can be recorded and additional data can be defined by the user. The plant items can be classified for unique identification (the existing plant item code is not always unique) and as a basis for technical descriptions. In addition to hierarchical structures, any other type of mutual relationship between plant items can also be displayed.

Items of equipment are the only products used in the plant to which maintenance measures are applied, and all relevant information (eg year of manufacture, service life, certification, settings, defects, repairs, servicing, findings) can be managed. The service life histories are used to optimise maintenance strategies and the availability status is available (installed in the plant, in stores, returned to the manu-facturer for repair).

Products used in the plant can be managed in a type catalogue. Data common to identical items are entered once; required com-ponents can then be found quickly by reference to their technical characteristics and a comprehensive record is available for the types used in the plant.

Type assignment allows the number of different types to be reduced and inventories to be optimised. Types are assigned with reference to the manufacturer or on the basis of a standard. Feature bars for describing ratings and versions together with all value ranges (possible entries) are already integrated into the system and can be modified by the user. Types can be assigned to items and stock numbers can be assigned to spare parts.

References to spare parts management, documentation, maintenance as well as continuous recording of service life form a powerful database for all kinds of information about the ‘economic’ power plant.

The maintenance management system records the plant’s life, adding dynamic information arising from operation and maintenance of the plant to the database. Occurrence management supports the systematic detection, reporting and processing of events. Order processing supports the planning, initiation, execution and documentation of jobs of all types. Repetitive tasks are described in work schedules and the initiating event (periodic, a function of operating hours or status-dependent) is specified.

When an event occurs, a work order is automatically initiated, and combined planning and processing of several work orders produces a work programme. Capacity scheduling supports personnel planning on a daily basis; for this purpose, a company calendar and a calendar that records the employee’s presence are managed in the system.

An equipment isolation function supports the planning, implementation and reversal of electrical switching and process engineering procedures to assure safety during work. Other occupational safety measures can be specified and recorded in the order and are checked by the system: the order is only released after implementation of the safety measures has been confirmed. The progress report allows the hours worked to be entered regularly and provides an overview of the progress of work.

Cost controlling provides a high level of time-based cost transparency in maintenance. The actual costs are calculated and compared with the estimated costs and the planned budget, and there is a subcontracted services function. Shift planning assigns personnel, and data and events are recorded for the individual shifts in the shift log.

With the static and dynamic information about the plant taken into consideration, the document management system handles the tons of paper work that still arises. In the BFS++ system document registration retains descriptions and version incrementations of documents in a central register. Apart from the standard references, such as KKS and key words, the documents can be directly assigned to all BFS items (eg part list items, equipment isolations).

The related documents can then be called from any BFS function and, if they are available in computerised form, they can be displayed immediately. Document archiving manages the storage locations and systematic storage of the documents. When documents are removed from the archive, the person involved, purpose and duration can be registered so that the document movements and archive inventories are known at all times.

For document distribution, parcels can be assembled in BFS++ and addressed — simplified by the standard distribution lists stored in the system. If this function is used consistently, it is easy to establish who has received what version of a document at any time. Deadlines for expected responses can also be stored in the system for follow-up and work flows can be established for processing documents.

In the spare parts management module of BFS++ the main emphasis is on stock optimisation, rapid access and conformance with technical requirements. The master stock management data are those required for the management of items (eg possible suppliers). Stores administration supports the efficient organisation of storage locations as well as material receipt, storage, issue and return of materials, and their relocation. Information overviews, such as the received materials book and the material movements book, supply comprehensive information at all times. Stock management supports both planning and execution of stocktaking, and also offers functions for evaluating and optimising stock levels.

The material requirements function ensures the availability of parts. The parts are usually specified and reserved when a work order is planned. When work is due to start, the storekeeper automatically receives the instructions to prepare for issuing the materials. If the stock level falls below the minimum requirements defined for an item, the system issues a prompt for re-ordering. Once this has been checked and, if necessary, corrected, an order proposal is transmitted to the department responsible. Purchase order processing comprises the functions of supplier inquiries, ordering and invoice checking. The data is loaded into the system and is available again on receipt of goods for checking purposes.

The engineering management system supports planning, execution, progress tracking and documentation of projects such as modifications and major overhauls. Projects can be clearly subdivided and assigned with the affected plant sections, documents, persons, etc. Further planning is performed with work programmes in which separate work steps are shown. Graphical bar charts are used for time scheduling at several hierarchic levels, while for detailed planning the work steps are transferred to order processing (part of the maintenance module). Flexible workflow management facilitates the planning, control and tracking of any work procedure.

The interface capacity makes it possible to avoid adapting one system for the complete range of requirements. Individual systems are used more effectively by linking existing data processing systems via interfaces — ‘best of breed’ links. Current operating data are used to implement condition-dependent maintenance and also for log output and reporting. The process interface allows operating hours or event counts to be read in from the process control system, as well as all other analog and binary values.

The link to the commercial administration systems allows data to be exchanged with the materials management, cost calculation and plant management functions.

The modular structure of the integrated system permits it to be introduced as a basic configuration with step-by-step extensions, and also allows individual functions to be selected to give a system that is tailored to user requirements.

Data fields, screen masks, catalogues and rules, printouts and even the work processes can be modified by the user. For this purpose special ‘configuration managing functions’ are available.

Any other functions that are required can be added using standard development tools.

BFS++ was developed using object-oriented programming using a language, Visual C++, which means that the system is independent of any one manufacturer (with the exception of Microsoft). Future adaptation is also assured by the object-oriented program structure of BFS++ and by total separation of the user software and data.

Any hardware platform ranging from a PC to mainframe can be used as the server, and a wide range of operating systems can be used. The BFS++

screen masks are designed uniformly in accordance with the Windows standard.

The Ertan project

The electric power industry in China is undergoing a transition from state-run and centrally controlled to market-oriented structures, and as a consequence the power generating industry is searching for new technology to improve productivity.

The first hydro project to use BFS++, the Ertan hydroelectric project, is situated on the Yalong River in the southwest of Sichuan Province. It is one of the largest hydroelectric power stations presently under construction in China, offering capacity of 3300MW and annual output planned at 17000GWh, it is a key project for energy development in the country. Each of the six penstocks has a diameter of 9m, while the parabolic double curvature arch dam is 240m high and dams a reservoir of 5.8km3 of river water.

In the cascade of 11 power stations along Yalong river, Ertan is the penultimate station before confluence with the Jinsha river to form the Yangtze. The first generating unit was due to be put into operation in June this year, and this was also the deadline for installation of the operational modules of BFS++.

The BFS++ project was divided in three phases. The first was installation and basic training, based on first modules with a user interface in English. The following step involved hanzification (conversion to Chinese language) and a second training and consultancy phase, in which the operational modules were implemented.

  Several fossil-fired power plants had already made use of the BFS++ system, and in order to allow the system to process the local Chinese letters Siemens Germany and Siemens China co-operated, so that the former made BFS++ doublebyte capable, and the latter provided the localisation.

Thanks to round-the-clock support from Siemens China in Beijing and Siemens Germany in Erlangen, communicating with the Siemens consultants on site via telephone and e-mail facilities, it was possible to finish the second phase in time and to the satisfaction of the customer before Ertan’s first unit started trial operation.

The third phase is due to be finished in October 1998. It will complete the scope of modules (mainly functions for top level management) as well as the closing out of consultancy services.