Computerized process-control systems

Computerized process control systems add complexity to operating instructions. These operating instructions need to describe the logic of the software as well as the relationship between the equipment and the control system otherwise, it may not be apparent to the operator. 

There are no detailed specihcation documents for any of the computerized process control systems that contain sufficient information on how these systems/software were represented and developed. The only specification documents made available and referred to as the design document were the system specifications however, these documents only provide a high-level explanation of what the systems do. They lack sufficient detailed description of specihc and complete data structure, data control flow, design bases, procedural design, development standards, and so on to serve as the model for writing code and to support future changes to the code. [FDA 483, 2000]... 

Failure to establish appropriate procedures to assure that computerized processing control systems and data storage systems are secure and managed to assure integrity of processes and data that could affect conformance to specifications. [FDA, 2001]... 

Automation. Computerized process control systems can be used for panel handling and process bath monitoring to prevent unexpected decomposition of a process bath, controlled rinse flow, and uniform panel withdrawal from each process bath. Since these systems require a significant capital expense for initial installation, typically only large printed circuit board companies will find this to be a cost-effective alternative. 

Full process control computerization for a multipurpose plant is much more complex and therefore will be also be much more expensive than for a dedicated single-product plant. Whenever possible, all efforts have to be made to choose standard process control systems and to apply standard control software this is a proven measure to control the investment costs in this segment and will also minimize the risk of having excessive investment and startup costs due to initiating problems with the computer control system. 

The approval of the qualification reports provides confirmation that the computer system as a whole is fit for its purpose, and that all essential documentation is available. For computer systems controlling manufacturing equipment (e.g., process control systems), the approval of the qualification reports indicate that the computerized systems is released for Process/Product Performance Qualification. On other computer systems, the approval of the reports releases the system to the user. 

A new recycle isotachophoretic process (93) uses a thin-film geometry with the electrical field perpendicular to the principal flow direction. Leading buffer, a marker dye, feed and trailing buffer are introduced into one end of the slit. An isotachophoretic stack develops perpendicular to flow as the liquid moves downstream. A fraction collector at the outlet collects the fractions, which are recycled until the stack sharpens. A computerized feedback control system keeps the stack centered in the apparatus. It regulates the withdrawal of trailing buffer and the addition of leading buffer in counterflow to the migration of the stack, based on the position of the marker dye front. 

During the OQ process, documented evidence is given that all parts of the plant and equipment work within their specifications and process parameters are within the acceptance criteria. Process controls that are part of the equipment (e.g., PLC [programmable logic controller]) will be qualified during the OQ process. Computerized process controls (i.e., for complex processes) should be qualified in the Computer Validation (CV) process. To ensure that the systems tested during OQ are doing what they are believed to do, a simulation of normal production conditions must be done. 

Cybersecurity. Deter cybersabotage, including by preventing unauthorized onsite or remote access to critical process controls, such as supervisory control and data acquisition (SCADA) systems, distributed control systems (DCS), process control systems (PCS), industrial control systems (ICS), critical business systems, and other sensitive computerized systems. 

Load sharing or selective load shedding is of interest to many users of hot gas expanders. A particularly successful European FCC application is illustrated in Figure 6-43. The addition of an expander-generator set to the FCC unit at a major refinery presented a challenge because a trip of the expander could upset the process. The company that is the subject of this application case study, GHH Borsig, solved this problem with the installation of a computerized control system and through computer simulation of trips. 

A National Transportation Safety Board Railroad Accident Report (1973) describes the accident which occurred in a shunting yard in East St. Louis, Illinois. Arriving cars are classified in the yard, then delivered to outbound carriers. On arrival, cars are inspected. They are then pushed up a mound, uncoupled, and allowed to roll down a descending grade onto one of the classification tracks. This process is called humping. Cars are directed and controlled by a computerized switching and speed-control system. 

The instrumentation of processing plants is fully computerized these days, and the use of distributed control systems (DCS) along with advanced network systems makes plant operations highly reliable. 

Is there a computerized, analytical results tracking and graphing system [process management software or statistical process control (SPC)] in place, as well as manual checks ... 

Narrowly focused, the tenets of 21 CFR 11 are indisputable that firms must establish and maintain the integrity of their electronic information. What has been lost is the clear indication of which electronic information the requirements apply to. In my opinion, data generated outside a computerized system, that are manipulated by that system and are ultimately available in hard copy should not be subject to this ruling. Validation of the computerized system should be more than sufficient to establish that the final documentation accurately reflects the input information. In that instance, the computerized system is little more than a tool whose functionality can be readily established, yet firms are endeavoring to assure 21 CFR 11 compliance for numerous systems in which the computer is little more than an adjunct to the cGMP activity and corresponding hard copy. Batch record preparation, SOP and test method archives, and many process equipment control systems are examples of systems in which requirements for 21 CFR 11 compliance appear excessive. A system that processes or communicates data or records and subsequently retains and stores hard copies should not be subject to the 21 CFR 11 requirements. Far too many systems are being unnecessarily held to the very restrictive portions of 21 CFR 11. Electronic record retention as defined in 21 CFR 11 has its place, but not necessarily in every computerized system used within the industry. 

Electrochemical calorimetry — is the application of calorimetry to thermally characterize electrochemical systems. It includes several methods to investigate, for instances, thermal effects in batteries and to determine the -> molar electrochemical Peltier heat. Instrumentation for electrochemical calorimetric studies includes a calorimeter to establish the relationship between the amount of heat released or absorbed with other electrochemical variables, while an electrochemical reaction is taking place. Electrochemical calorimeters are usually tailor-made for a specific electrochemical system and must be well suited for a wide range of operation temperatures and the evaluation of the heat generation rate of the process. Electrochemical calorimeter components include a power supply, a device to control charge and discharge processes, ammeter and voltmeter to measure the current and voltage, as well as a computerized data acquisition system [i]. In situ calorimetry also has been developed for voltammetry of immobilized particles [ii,iii]. 

Packaging and Labeling System (including validation and secinity of computerized processes, change control, and training/qualihcation of personnel)... 

Lack of validation of computerized processes Pattern of failure to establish/follow change control process Production System... 

Provide a hst of all GxP-related computerized systems on site by name and application for business, management, information, and automation (equipment and process control) levels. Indicate the totahty of the inventory of computerized systems and indicate links with other sites/networks, etc. 

OQ verifies that the control and monitoring instrumentation, as integrated with the process equipment and any associated computerized control system, meets the operational and functional requirements defined in the instrument application design documentation and/or computerized control system User Requirements Specification (URS). PQ verifies that the control and monitoring instrumentation, as integrated with the process equipment and any associated computerized control system, meets the operational and functional requirements defined in the instrument application design documentation and/or computerized control system URS, and prodnces pharmaceutical product consistently to specification. ... 

Periodic reviews of the mannfacturing process, inclnding the control and monitoring instmmen-tation and any associated computerized control system, mnst take place from the time it is handed over to a site nntil it is replaced and/or decommissioned, in order to verify that it continnes to be capable of prodncing qnality product to specification. The pnrpose of a periodic review, with regard to control and monitoring instrumentation, is to verify that it has been maintained in a validatable condition. 

As previously described, the use of computers and computerized systems in the pharmaceutical industry is growing at a rapid rate. Some of the systems used in the industry range in complexity from the use of personal computers for performing simple tasks (word processing, e-mail, Internet access) to the use of powerful computers in process-control applications. In addition, to help eliminate or reduce paper usage, the pharmaceutical industry has implemented a number of electronic batch record systems in drug substance and product manufacturing to keep track of process documentation. 

A representative sample should be taken for the purpose of performing a retest. The company s overall policy, intentions, and approach to validation, including the validation of production processes, cleaning procedures, analytical methods, in-process control test procedures, computerized systems, and persons responsible for design, review, approval, and documentation of each validation phase, should be documented. The critical parameters/attributes should normally be identified during the development stage or from historical data, and the necessary ranges for the reproducible operation should be defined. This should include ... 

In the era of single-loop control systems in chemical processing plants, there was little infrastructure for monitoring multivariable processes by using multivariate statistical techniques. A limited number of process and quality variables were measured in most plants, and use of univariate SPM tools for monitoring critical process and quality variables seemed appropriate. The installation of computerized data acquisition and storage systems, the availability of inexpensive sensors for typical process variables such as temperature, flow rate, and pressure, and the development of advanced chemical analysis systems that can provide reliable information on quality variables at high frequencies increased the number of variables measured at... 

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