Computer system requirements

COMPUTER SYSTEM REQUIREMENTS (Hardware, Software, Support, Etc.)... 

In summary, producing a computer system requirements specification in the form of the URS provides the following key benefits for the validation program ... 

Design qualification is a formal and systematic verification that the computer system requirements specification is met by succeeding system design specifications and their implementation throughout the development and build (including development testing) activities. 

Definitions. Each business group will have a set of worxing words and definitions to describe computer systems and their operations and functions within the group. These should be listed and clearly defined in the SOP. The key definition needed is for a computer system requiring validation a "validatable system". The practical determination of validatable systems in day-to-day operations is the responsibility of the operating committee. 

When the criticality and complexity (Refer to Appendix D) of the computer system requires that standard product source code be made available, the legal department of the pharmaceutical company should negotiate one of the following written agreements with the software developer. 

Every exposure assessment should have a protocol written before its initiation. This protocol should hrst state the purpose of the exposure assessment and the model(s) used therein. It should also include the variables to be evaluated (i.e. a clearly defined assessment endpoint), the level of detail needed, how uncertainty will be addressed, and the relationship of uncertainty to the conclusions that may be drawn. Furthermore, the protocol should describe each of the other principles of practice noted below in sufficient detail so that the assessment is clearly adequate for the purpose. Similarly, exposure models used in assessments should be accompanied by adequate documentation regarding procedures for using the model, plus the minimum information that is required as input data and software references and computer system requirements. 

The EU published its Good Clinical Practice for Trials of Medicinal Products in 1991. The U.S. had no single equivalent to the EU GCP document. Computer system requirements in the EU GCPs ineluded ... 

During the operational life of the computer system, requirements traceability will enable impact assessments to be conducted in support of regression testing of changes. It is quite normal for a particular aspect of a computer system to require more than one test. When making a change, it is important to appreciate if this one-to-many situation exists and ensure that all appropriate tests are executed. 

An early decision as to whether a computer system requires validation or not can help ensure that the necessary support for validation is provided for at the outset of a project. Late identiflcation of validation requirements could result in significant costs and delays if additional activities and documentation are required. In addition, many regulatory authorities devalue such retrospective validation. 

Computer systems require validatiou wheu au affirmative answer must be giveu to oue or more of the followiug questious ... 

The first risk assessment that needs to be done when implementing a new system is one that may often be skipped because the result often seems quite obvious this is the decision as to whether or not the computer system requires validation. However, leaving this assessment out can lead to regulatory liability in regard to systems that a firm decides do not need validation, so it is advisable to make this assessment a standard expectation within the company s system development methodology. It is not an onerous expectation, as it usually takes only a few minutes to document the decision properly. 

Minimum computer system requirements for successfully running this software. In addition to basic computer system requirements, this information also covers enabling Java (necessary to run the quizzes in the Quizzing section), and checking/ changing your computer s video display resolution so that you can view the contents of the site with less scrolling. 

Not all computing systems require an operating system whether one is needed or not depends upon the application of the computing system. Generally, operating systems are not required where... 

Verifiability is improved when documents are understandable, unambiguous and traceable. Use of the same model or language for computer system requirements through software requirements and software design will also aid verifiability, but is not necessarily a solution to all problems. When formal langnages are used to specify requirements or designs, theorem provers and model checkers may also aid in verifiability. 

Validation should be performed to demonstrate that the computer system achieves its overall safety and functional requirements. There are two distinct steps of validation. The first step is the validation of the computer system requirements against the plant and system requirements (see para. 2.6). The basis for this validation against these higher level requirements and safety analyses should be explicitly identified in the validation report. The second step is the validation of the computer system implementation against the computer system requirements. Techniques and... 

The computer system requirements define, as a minimum, the functional and non-functional properties of the computer system that are necessary and sufficient to meet the safety requirements for the plant that have been defined at a higher design level. The specification of computer system requirements is a representation of the necessary behaviour of the computer system. Precise defiiution of the interfaces to the operator, to the maintainer and to the external systems is an integral part of the product provided as the output of this phase. At this stage, the definition of interfaces is limited to the functional and non-functional properties of these interfaces then-design or implementation may be as yet undetermined. 

The derivation of these requirements is a critical step in the development process because errors and deficiencies at this stage will eventually challenge the validation process if not detected during development. Additionally, defects in the computer system requirements are a potential source of common cause failures in redundant subsystems containing identical software. 

The computer system requirements should be independent of the implementation. They should deal with the computer system as a black box. A formalism for specifications that is understandable to all parties concerned, with a well defined syntax and semantics, should be used to capture the results of that woik. This formalism should be understandable to the licenser, suppliers and designers of the computer system and the software specifications. The formalism can be supported by tools that help in the validation of the completeness and consistency of the requirements. 

The description of the computer system requirements should be easy to use in order to verify the adequacy of the computer system and the software spedfications and to define the specifications of the tests that will validate the system when the design is complete. 

Tools used to analyse the consistency and completeness of the computer system requirements should be validated to a level of confidence proven to be equivalent to the level required from the design process described in paras 5.10-5.23. 

As part of the system safety demonstration, the computer system requirements should be subjected to a failure analysis. Potentially incorrect system outputs should be identified, their impact on the plant and the environment should be evaluated, and adequacy of defence in depth should be confirmed. 

The computer system architecture selected should provide the system interfaces specified by the computer system requirements and should implement the nonfunctional computer system requirements, such as those pertaining to performance and reliability. 

The computer system design shonld also cover non-funchonal aspects of the computer system requirements such as the ability to cope with extreme temperatures,... 

The documents for the computer system design should be part of a document continuum which starts with the specification of the system requirements. The parts of the system requirements which pertain to the computer system are brought forward into computer system requirements. In some cases, the functional and performance requirements contained in the system requirements are brought forward without change, but more often they are refined to a lower level of abstraction to reflect details or decisions made which are pertinent to the computer system. 

The computer system requirements include reliability or availability requirements, and these requirements should be carried forward into the software and hardware. Given the reliability required of the computer based system and the reliability that can be expected from the hardware, it may be that certain software requirements should be included so that the system will be able to meet its reliability targets (see Section 6). 

A traceabihty analysis should be performed to demonstrate that the validation requirements (for test or evaluation) are complete with respect to the computer system requirements. 

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