Plant computer system

The applicability of these findings for actual operational tasks was evaluated by considering the incidence of data entry errors recorded by the on-line plant computer system over the 24-hour shift cycles. It was judged that the data entry task, which involved evaluating the set point changes needed for... 

Plant computer system— Provides computational, data processing, and data presentation services for the plant. Flow maps and instrumentation diagrams may be called-up and data-logged to allow sequence analysis after events. Computers are especially valuable in the training center to model the reactor and all other systems, and to simulate upset and accident conditions that could not be conducted on the actual plant. This tool is also important in the development of emergency procedmes. 

Computer Science Analyst. Start 29.30 per hour 60,944 per year. Bachelor of Science in Computer Science. Maintain plant computer systems. 

The data display and processing (plant computer) system is implemented in a distributed architecture. The working elements of the distributed computer system are graphics workstations, although their graphics capability is secondary to their computing performance. The distributed computer system obtains its input from the real-time data network and delivers its output over the network to other users. 

The KDF filter was first tested in prototype on a coal mine in northern Germany. It was installed in parallel with existing vacuum filters and it produced filter cakes consistendy lower in moisture content by 5 to 7% than the vacuum filters. Two production models have been installed and operated on a coal mine in Belgium. The filter is controlled by a specially developed computer system this consists of two computers, one monitoring the function of the filter and all of the detection devices installed, and the other controlling the filtration process. The system allows optimization of the performance, automatic start-up or shut-down, and can be integrated into the control system of the whole coal washing plant. 

Stand-alone computer systems, usually based on a personal computer (PC) or programmable logic controller (PLC), provide a separate computer system for each pilot plant. This allows for economical expansion for new units, separates pilot plants completely for maintenance and troubleshooting, and often has the lowest initial cost. Standardization can be a problem and software control, data gathering, and storage packages can be limited in size, scope, and capabiUty these are usually acceptable trade-offs. 

Coal Slurry Pipelines. The only operating U.S. coal slurry pipeline is the 439-km Black Mesa Pipeline that has provided the 1500-MW Mohave power plant of Southern California Edison with coal from the Kayenta Mine in northern Arizona since 1970. It is a 457-mm dia system that aimuaHy deHvers - 4.5 x 10 t of coal, the plant s only fuel source, as a 48.5—50% slurry. Remote control of slurry and pipeline operations is achieved with a SCADA computer system. In 1992 coal deHvery cost from mine to power plant was calculated to be 0.010/tkm ( 0.015/t-mi) (28). 

They attend to and control different technical plants and systems, and they have to deal with all processes required. In data-based plants, controllers usually communicate with one or several local or central computers. 

When local or central computers are used for controlling the operation of HVAC installations in buildings, they are described as building automation systems. In the control station, operators communicate with control installations, which are connected through the computer plant. Computers for individual use are called personal computers (PCs). The use of PCs for technical and economic tasks in the past few years has increased considerably. The business overflows with PCs, which get greater data power and memory at lower prices. 

Nimmo, S. R. Nunns, and B. W. Eddershaw, Lessons Learned from the Failure of a Computer System Controlling a Nylon Polymer Plant, Paper presented at Safety and Reliability Society Symposium, Altrincham, UK, Nov. 1987. 

The relevance of the information to the process worker is another factor in design. This principle is often violated with the introduction of new VDU-based computer systems where information needed to assist computer scientists or production managers is mixed with information relevant for the safe operation of the plant. Clearly, some kind of structuring and prioritization will be necessary for the different users of the system. 

Also located in the control room is the manual-automatic switching hardware (or software). During start-up or under abnormal conditions, the plant operator may want to be able to set the position of the control valve himself instead of having the controller position it. A switch is usually provided on the control panel or in the computer system as sketched in Fig. 7.2. In the manual position the operator can stroke the valve by changing a knob (a pressure regula-... 

The concentration of all automation functions within a single computer (Section 7.19.1) may be possible for a very simple plant, but this type of configuration is inefficient for more complex processes for which there could be many thousands of connections between plant and computer. Currently, small industrial processes are controlled by a hierarchical architecture consisting of a central computer (usually a minicomputer), which is used to solve central automation problems, together with a series of peripheral computers (generally microprocessors which are called front-end computers) which control different sections of the plant (Fig. 7.104a). This type of architecture is termed a decentralised computer system. 

To maintain control of the computer system throughout its conception, implementation, and operational use in a GMP environment, it is required that the computer system application must be validated in a way that will establish auditable documented evidence that the computer system does what it is expected to do. As applicable, this needs to be carried out in conjunction with plant equipment to provide a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes. The methodology to achieve this is based on a recognized life-cycle mode. 

In the case of a computer system applied to a live manufacturing process and integral with plant equipment and the process itself, the project validation plan should specify the relationship of the computer system qualification activities and documentation with that of the corresponding plant equipment qualification and process validation. Indeed, the qualification activities and documentation of these elements of a computerized operation are sometimes combined. 

In the majority of cases, the application of a computer system to pharmaceutical manufacturing is part of a capital investment involving other items of production plant equipment and a wide range of contracted design, installation, and commissioning activities carried out by appropriate engineering disciplines. 

For a stand-alone system the computer system normally undergoes factory acceptance testing at the supplier s premises, and as with associated instrumentation and regulating devices is shipped to the site, inspected, and where applicable is stored and then installed with the manufacturing process/plant equipment. 

On satisfactory completion of SAT the system can be considered as available for plant operational commissioning. The computer system SAT report should document a high level of confidence in the computer system (i.e., the computer integrated with the field instrumentation and controlled function) in readiness for in situ site qualification testing activities. 

Operation qualification involves a high degree of dynamic testing of the computer system in conjunction with the controlled process. It normally uses an alternative medium to represent process conditions, and can be performed in conjunction with plant and equipment engineering commissioning. Operation qualification testing may include both normal and abnormal operating conditions. 

For computer systems that are an integral part of the operation of a manufacturing plant or process, the system PQ may be conducted in conjunction with process validation. The combined activities are generally led by the pharmaceutical manufacturer s quality assurance function and can be in the form of an extended process trial. 

This life-cycle phase will normally involve all parts of the computerized operation, not just the computer system. It is therefore essential that other equipment such as operating plant, utilities, and services that are part of or related to the manufacturing process have also been qualified or commissioned to the appropriate level prior to commencing PQ. 

Performance qualification involves performing a number of production runs (traditionally, at least three) that are considered to be representative batch sizes for the operation. These are to be conducted using pharmaceutical product and utilizing the computer system and services of production operatives as stipulated in the URS and plant SOPs. 

Objective and Scope. The objective and scope of the SOP need to be carefully thought through and described. A limited objective could be to validate only those computer systems directly related to the production of pharmaceuticals the broadest one would be to validate all computer systems regardless of their application. Usually it is somewhere between the two. The scope will be determined by the company philosophy, organizational structure and the number of divisions, plants or departments involved. The scope should be limited to as small a unit as possible for the initial validation effort in order to achieve at least one successful computer system validation quickly. 

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