CONTROL SYSTEMS

Selection of a control strategy for a pharmaceutical water system should consider feed water quality and reliability, the complexity of the purification and/or distribution system, labor costs, personnel skill levels and capabilities, and documentation and reporting requirements. Options for control include:

a) Local instrumentation with manual control: In this option, a combination of instrumentation, periodic samples, and visual examination is used to monitor critical process parameters. Data is collected and recorded manually, and analysis and trending capabilities are limited. Excursions of critical parameters outside acceptable ranges typically trigger local alarms to reduce the risk of unacceptable water quality.

Satisfactory manual operation requires significant human intervention. This requires detailed operating procedures and conscientious documentation of critical quality parameters. This option has the lowest installed cost, but is very labor intensive and may be subject to human error.

b) Semi-automatic control: These systems use local operator control panels, relay logic control, local chart recorders and printers, and some manual data collection to monitor and control the water system.

These systems are less labor intensive over the manual systems, but are still labor intensive due to the manual data collection and monitoring required to control the process.

c) Automatic control: Automated systems use a computer (PLC or DCS), or computers, to control the pharmaceutical water system. The computer system utilizes appropriate process monitoring instrumen-tation (conductivity probes, flow meters, etc.) to gather data and make appropriate adjustments to the system automatically. As water generation systems become more sophisticated, relying on human inter-vention to control and monitor the water system becomes more difficult and labor intensive. An auto-mated system requires less operator involvement, but requires a more highly trained maintenance and engineering support staff.

d) Fully integrated systems: These systems include a fully automated system and a wide area network connected to other computer systems in the building or site. These systems allow for central site monitor-ing, automatic electronic data collection, centralized alarm monitoring with automatic recordmonitor-ing, response, and report generation.

Additional information on control system design is available in the Good Automated Manufacturing Practice (GAMP) Guide and in various guidelines by the Instrument Society of America (ISA).

Whichever level of automation is selected, the validation effort should verify operation of the complete sys-tem, including vendor-supplied sub-systems.

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9.6.2 Control System Software

The software/control system may be used to measure, monitor, control, or record critical process param-eters. Programming and design standards, especially concerning operator interface, control techniques, alarm handling, and interlock processing should be applied during the development, validation and maintenance phases of the project. The control system software consists of:

a) Firmware, Operating System and Application Software: This is software permanently loaded into memory that may or may not be accessible to the user. While the functions performed by the control system may be divided between critical and non-critical functions, it is impossible to divide or isolate the firmware, operating system, application software, and associated hardware functions. Therefore, if some of the functions of a control system are considered critical, all of the above software is considered critical, and should be validated.

b) User Configurable Software: The functions of the user configurable software may be defined as critical or non-critical. The critical functions or modules require enhanced documentation, including validation. In some cases, it may be impossible to divide or isolate software adequately. In such cases, if some of the functions are critical, it may be necessary to validate all the software.

The type of process control required is often the determining factor in the type of software needed, and software requirements often define the type of system selected. Major considerations are:

• Number of I/0 points

• Mathematical or statistical functions required

• Reporting features required (particularly if the control system is to be further integrated into higher sys-tems)

• Whether or not advanced control techniques are required (e.g., neural nets; fuzzy logic controllers; adap-tive gain; dead-time compensation)

9.6.3 Control Hardware and Operation Interface

a) Critical software requires enhanced documentation and should be designed and tested in accordance with the Lifecycle Methodology.

b) The water system, field instruments and control requirements all affect control hardware selection. Plant standards, or a large installed base of a particular system may drive the selection.

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QUALIFICATION

Mr. Shlomo Sackstein Herzlia,

ID number: 216389

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10. COMMISSIONING AND QUALIFICATION

10.1 INTRODUCTION

Commissioning and qualification comprise the validation process by which a system is put into service and demonstrated to consistently produce water of a specified quality, under various conditions, while operated under set procedures. Although commissioning and qualification are typically separated within a project sched-ule, they are in essence, one continuous process.

The specific activities and processes during commissioning and qualification will not be discussed in this Guide. These are considered by a separate ISPE Baseline^® Guide on Commissioning and Qualification, and pharmaceutical water systems are used as examples throughout. A summary of key concepts are listed below:

a) Due to the interdependence between activities and those involved, excellent communication, planning and coordination between operations, engineering, commissioning, and validation personnel will enable timely and cost-effective project completion.

b) Each component of the system should be built in accordance with plans and specifications and should be inspected, tested, and documented by qualified individuals. These activities, and the production of sup-porting documentation, are defined as Good Engineering Practice (GEP).

c) GEP recommends a minimum level of documentation for all systems and equipment. This encompasses design, fabrication, vendor testing, construction, field inspection, and commissioning. If these documents are appropriately planned, organized, and authorized, they may become an integral part of qualification support documentation, thus avoiding redundancy and saving time and money.

d) Design criteria and documentation requirements should be clearly defined early in the design phase, to ensure clear expectations and appropriate planning, and facilitate timely commissioning and validation.

Engineering firms, vendors, and contractors should be required, per the system specifications, to provide the necessary documentation, to avoid unnecessary costs and delays associated with obtaining or cre-ating these documents.

e) During construction, timely review of documentation and periodic “walk-throughs” can ensure that Instal-lation Qualification requirements are met.

f) Commissioning takes the system from a state of substantial completion to a state of operation. It is the phase of a project that includes mechanical completion, start-up, and turnover. Commissioning incorpo-rates a systematic method of testing and documenting the system at the conclusion of construction, and prior to the completion of validation activities.

g) Commissioning documents should not be created and executed for the purpose of regulatory compli-ance. However, commissioning tests and documentation will typically satisfy many installation and op-erational qualification requirements.