Control change

Various accessories can be suppHed along with the control valves for special situations. Positioners ensure that the valve stem is accurately positioned following small or slowly changing control signals or where unbalanced valve forces exist. Boosters, which are actually pneumatic amplifiers, can increase the speed of response or provide adequate force in high pressure appHcations. Limit switches are sometimes included to provide remote verification that the valve stem has actually moved to a particular position. 

Control in the wrong position Control settings do not change Control settings may be purposefully changed for different phases of batches, different batches or similar batches... 

Procedures and instru- Standardize on commonly accepted units and ments have different keep them consistent Provide conversion charts and look-up tables Provide change control to ensure devices and procedures are synchronized Update procedures to include appropriate unit conversion data CCPS G-32... 

Craven, P.J. (1999) Intelligent Control Strategies for an Autonomous Underwater Vehicle, PhD Thesis, Department of Mechanical and Marine Engineering, University of Plymouth, UK. Craven, P.J., Sutton, R. and Burns, R.S. (1997) Intelligent Course Changing Control of an Autonomous Underwater Vehicle. In Twelfth International Conference on Systems Engineering, Coventry, UK, September, 1, pp. 159-164. 

These may change after tests and trials and therefore need to be brought under change control following the document approval. 

Modification instructions should be produced after approval for the change has been granted and should be submitted to the change control board or design authority for approval before release. 

The evaluation may need to be carried out by a review team, by subcontractors, or by the original proposer however, regardless of who carries out the evaluation, the results should be presented to the change control board for a decision. During development there are two decisions the board will need to make ... 

During production the change control board will need to make four decisions ... 

Set up a design change control board to review, evaluate, and approve or reject design changes. 

Do commence change control immediately after the design requirement has been agreed and issued. 

Produce procedures for preparing, reviewing, approving, issuing, and changing controlled documents. 

Don t create a complex change control mechanism - it should represent the easiest way of changing a document. 

This element covers the translation of customer specifications for the product into the corresponding specifications for materials, products, and processes. Design reviews, product and process acceptance criteria, design change control, and design requalification are all addressed. 

This element covers preventive maintenance, management of change (process change control) and verification practices, and frequencies for quality... 

The documentation system should include guidelines regarding the access of records by customers and suppliers, change control procedures, the types of records to be collected, and specifications for indexing, filing, storage, maintenance, retrieval, and disposition. 

Lieberman, N. P, Change Controls to Save Energy, Hydrocarbon Processing, Feb., (1978) p. 93. 

In a phase-change controlled thermal management system, the energy associated with phase change will account for most of the heat removal... 

This system assures overall compliance with cGMPs and internal procedures and specifications. The system includes the quality control unit and all of its review and approval duties (e.g. change control, reprocessing, batch release, annual record review, validation protocols, and reports, etc.). It includes all product defect evaluations and evaluation of returned and salvaged drug products. 

The software life cycle activities extend until retirement of the software. However, in a manner of speaking, life cycle activities extend even beyond retirement since the data must be able to be reconstructed at any time during the life of the product, i.e., the archived record must always be accessible and readable even if the software is no longer commercially available or typically employed in the laboratory. Additional software validation includes implementation of the code and integration and performance testing. There also must be system security, change control procedures, audit trails, calibration, preventative maintenance, and quality assurance. 

The validation umbrella not only covers in-house systems, but also covers vendor systems. Much of industry today is dependent to some extent on vendor-supplied electronic systems and, consequently, the vendor s validation of those systems. Because of this, there are validation issues to assess at the vendor including how the vendor addresses change control, testing and documentation, source code, integration, and implementation of the system during development. Implementation support also must be assessed. 

Are there management approvals/acceptance for change control ... 

Develop policy-supporting SOPs on computer systems. These may include development, testing, maintenance and support, quality assurance, change control, source code management, system retirement, retrospective evaluation, evaluation of vendor-supplied systems, etc. 

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