Maintenance in electrical and integrated  control systemem

Generally

The maintenance service for a company´s process machinery is of vital significance or importance for operating security it´s availability and reliability.
To ensure operating security it´s availability and reliability, computer functions shall be available for stop planning, material storage etc.
A log system shall be available who continuously and rapidly supervise the machinery and functions state.
Disturbances and failures shall be indicated and reported to aid  maintenance people in quickly  repairing the failure.
In continuous processes where every stop implies loss of production and increased costs, is that important.
For exmple, a modern papermachine that produces newspaper continousuly 24 hours a day will cost about 100000 swedish crown every hour the machinery remains idle.
With such stop-time costs, it is easy to understand how important it is to minimize stop time.
 

Operating security in the process industry.

Profitability in process industries depends on many factors. Operating security is of gratest significance.
When planning and making projections for a plant, it is critically important to deal with fundamental security questions.
It is important to select correct, highly reliable equipment and components and to accurately determine the equipment´s maintenance issues in prevention and acute maintenance.     .
It is also important that maintenance activity is well organized and that the competence of maintenance presonnels matches the complexity needs of the equipment.
Redundancy requirements are sometimes necessary in complex electronic systems. In that way, it may be possible to avoid process stoppage due to disturbances in the control system.

Factors that influence operating security

Operating security is measured by process availability and depends on the security requirements in the process, ability in maintenance, and maintenance security.

Security in complex integrated functions
is measured by the probability of failure and is mentioned as the number of failure per unit of time or in average time between failure, MTBF (Mean Time Between Failure ).

Ability in maintenance
are measured by what is required in equipment repairs and maintenance and can be measured by time of repair and costs of repairs per failure.

Maintenance security
depends on the resources and maintenance organization such as: personnel, spare parts, assistance for maintenance etc.and can be measured by costs for spare parts and waiting time for failure repair.

Security in operation depends, therefore, partly on the equipment´s technical performance, partly on the components´ quality for reliability and  accuracy, and partly on the maintenance availability of personnel resources, technical assistans and spare parts.

Summary

To sum up, we can say that operating security has the gratest impact on the profitability of an industrial investment in the short as well as long view.
It is seldom profitable to install equipment at the lowest costs, if one fears increased problems with security.
Therefore, it is important during all phases of a project, from pre-planning to starting operation-to think about the security questions both in strictly profitable view and in personnel security view.
In the planning and the thechnical build up of control systems, it is necessary to test the demand on functions and components.
It is also particularly importment to study the technical build-up of personnel from both a security and maintenance view.
It is also important to think about how the process equipment will be adapted to meet increased production volume and quality.
It is a doubtful investment to implement existing old equipment with a more accuracy control system if the process equipment doesn´t  have adequate performance.
It is important to take into consideration that installed equipment shall function well for a profitable production during the equipment´s total life time with an adpted maintemance service.
The resulting operation security depends on the equipment´s failure frequency, partly on the maintenance organizations capacity to realize prevention maintenance and to anticipate failure.
Both material and personnel resources should be availibel and adapted to the equipment.
Of gratest important is also the dokumentation for operation security.
The dokumentation must be well-structured and well-organizt so that the maintenance function shall operate quickly and well without too long a stoppage in the operation.
The dokumentation shall be adapted to what you need so that everyone who needs it gets the basic he needs in his work .
Well-made dokumentation adapted to the user increases the equipment´s availability and reduse operating and maintenance costs.
Finally, the education of personnel is important to the security. Maintenance personnel competency must be adapted to the equipments technical level.
In the case of existing equipment or in new or changed equipment, personnel must complete or renew their education.

Se also  Security in an integrated control system
 

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