Verification & Validation is the process of checking that a product, service, or system meets specifications and that it fulfils its intended purpose. These are critical components of a quality management system such as ISO 9000.
Verification is a quality process that is used to evaluate whether or not a product, service, or system complies with a regulation, specification, or conditions imposed at the start of a development phase. Verification can be in development, scale-up, or production. This is often an internal process.
Validation is the process of establishing documented evidence that provides a high degree of assurance that a product, service, or system accomplishes its intended requirements. This often involves acceptance and suitability with external customers.
It is sometimes said that validation can be expressed by the query ‘Are you building the right thing?’ and verification by ‘Are you building the thing right?’. 'Building the right thing' refers back to the user's needs, while 'building it right' checks that the documented development process was followed. In some contexts, it is required to have written requirements for both as well as formal procedures or protocols for determining compliance.
Activities
Verification of machinery and equipment usually consists of Design Qualification - DQ [1], Installation Qualification - IQ [2], Operational Qualification - OQ [3] and Performance Qualification - PQ [4]. DQ is usually a vendor's job. However, DQ can also be performed by the user, by confirming through review and testing that the equipment meets the written acquisition specification. If the relevant document or manuals of machinery/equipment are provided by vendors, the later 3Q needs to be thoroughly performed by the users who work in an industrial regulatory environment. Otherwise, the process of IQ, OQ and PQ is the task of validation. The typical example of such a case could be the loss or absence of vendor's documentation for legacy equipment or DIY assemblies (i.e. cars, computers etc.) and, therefore, users should endeavour to acquire DQ document beforehand. Each template of DQ, IQ, OQ and PQ usually can be found on the internet respectively, whereas the DIY qualifications of machinery/equipment can be assisted either by the vendor's training course materials and tutorials, or by the published guidance books, such as step-by-step series if the acquisition of machinery/equipment is not bundled with on- site qualification services. This kind of the DIY approach is also applicable to the qualifications of software, computer operating systems and a manufacturing process. The most important and critical task as the last step of the activity is to generating and archiving machinery/equipment qualification reports for auditing purposes, if regulatory compliances are mandatory. At the same time, one should bear in mind to kindly share the original work with others, if the activity, especially validation of newly invented machinery/equipment, is worth of publishing.
Qualification of machinery/equipment is venue dependent and re-qualification needs to be conducted once the objects are relocated. The full scales of some equipment qualifications are even time dependent, and hence re-certification is necessary when a specified due time laps [5],[6]. Re-qualification of machinery/equipment should also be conducted when replacement of parts, or coupling with another device, or installing a new application software and restructuring of the computer which affects especially the pre-settings, such as on BIOS, registry, disk drive partition table, or an ini file etc, have been necessary. In such a situation, the specifications of the parts/devices/software and restructuring proposals should be appended to the qualification document whether the parts/devices/software are genuine or not. Torres and Hyman have discussed the suitability of non genuine parts for clinical use and provided guidelines for equipment users to select appropriate substitutes which are capable to avoid adverse effects [7]. In the case when genuine parts/devices/software are demanded by some of regulatory requirements, then re-qualification should not be conducted on the non genuine assemblies. In stead, the asset has to be recycled for non regulatory purposes.
When machinery/equipment qualification is conducted by a standard endorsed third party such as by an ISO standard accredited company for a particular division, the process is called certification [8],[9]. Currently, the coverage of ISO/IEC 15408 certification by an ISO/IEC 27001 accredited organization is limited, the scheme requires a fair amount of efforts to get popularized.
Categories & aspects of validation
Validation work can generally be catogrized by the following functions:
Prospective validation - the missions conducted before new items are released to make sure the characteristics of the interests which are functional properly and which meet the safety standards [10],[11]. Some examples could be legislative rules, guidelines or proposals [12],[13],[14], methods [15], theories/hypothesis/models [16],[17], products and services [18],[19]
Retrospective validation - a process for items that are already in use and distribution or production. The validation is performed against the written specifications or predetermined expectations, based upon their historical data/evidences that are documented/recorded. If any critical data is missing, then the work can not be processed or can only be completed partially [10],[20],[21]. The tasks are considered necessary [22] if
prospective validation is missing, inadequate or flawed.
the change of legislative regulations or standards affects the compliance of the items being released to the public or market.
reviving of out-of-use items
Some of the examples could be validating of the ancient scriptures that contain controversies [23],[24], clinical decision rules [25], data systems [26],[27] etc.
Full scale validation
Partial validation - often used for research and pilot studies if time is constrained. The most important and significant effects are tested. From an analytical chemistry perspective, those effects are selectivity, accuracy, repeatability, linearity and its range.
Re-validation/Locational or Periodical validation - carried out, for the item of interest that is dismissed, repaired, integrated/coupled, relocated, or after a specified time laps. Examples of this category could be relicencing/renewing driver's license, recertifying an analytical balance that has been expired or relocated, and even revalidating professionals [28],[29].
Concurrent validation - conducted during a routine processing of services, manufacturing or engineering etc. Example of these could be duplicated sample analysis, single sample analysis with multiplicated online system suitability testings
The most tested attributes in the validation taskes may include
Selectivity/specificity
Accuracy
Precision/Repeatability
Reproducibility
Curve fitting
System suitability - In a broad way, it usually includes a test of ruggedness among inter-colaborators or a test of robustness within an organization [30],[31],[32]. However, FDA has specifically defined it for its administration, as "System suitability testing is an integral part of many analytical procedures. The tests are based on the concept that the equipment, electronics, analytical operations and samples to be analyzed constitute an integral system that can be evaluated as such. System suitability test parameters to be established for a particular procedure depend on the type of procedure being validated." A good example is provided by the company of GMP ONLINE CONSULTANCY and the test requires certified standards if a compendial method is to be used [33].
Industry references
These terms generally apply broadly across industries and institutions. In addition, they may have very specific meanings and requirements for specific products, regulations, and industries. Some examples:
Pharmaceuticals The design, production, and distribution of drugs are highly regulated. This includes software systems. For example in the USA, the Food and Drug Administration have regulations in Part 21 of the Code of Federal Regulations [1]. Nash et al. have published a book which provides a comprehensive coverage on the various validation topics of pharmaceutical manufacturing processes [34]. Some companies are taking a risk-based approach to validating their GAMP system if one understands the regulatory requirements very well while the most of others follows the conventional process [35],[36]. It is a part of GxP management.
Medical devices The FDA (21 CFR) has validation and verification requirements for medical devices. . See guidance: [2] and ISO 13485
Manufacturing process and cleaning validation are compulsory and regulated by FDA[10],[37],[38],[39].
Clinical laboratory medicine: ISO 15198:2004 Clinical laboratory medicine -- In vitro diagnostic medical devices -- Validation of user quality control procedures by the manufacturer
Greenhouse gas: ISO 14064 ANSI/ISO: Greenhouse gases — Requirements for greenhouse gas validation and verification bodies for use in accreditation or other forms of recognition
Agriculture - applications vary from verifying agricultural methodology and production processes to validating agricultural modeling [40],[41],[42],[43],[44].
^ Quinn, James et al. (2006). "Prospective Validation of the San Francisco Syncope Rule to Predict Patients With Serious Outcomes". Annals of Emergency Medicine (Elsevier) 47 (5): 448 - 454. doi:10.1016/j.annemergmed.2005.11.019.
^ Sangiovanni, A. et al. (2007). "Prospective validation of AASLD guidelines for the early diagnosis of hepatocellular carcinoma in cirrhotic patients". Digestive and Liver Disease (Elsevier) 40 (5): A22 - A23. doi:10.1016/j.dld.2007.12.064.
^ Van Geest-Daalderop, Johanna H. H. et al. (2008). "Improvement in the regulation of the vitamin K antagonist acenocoumarol after a standard initial dose regimen: prospective validation of a prescription model". Journal of Thrombosis and Thrombolysis (Springer). doi:10.1007/s11239-008-0203-4.
^ Ames, D. et al. (1996). "Prospective validation of the EBAS-DEP -- A short sensitive screening instrument for depression in the physically ill elderly". European Psychiatry (Elsevier) 11 (Supplement 4,): 361s. doi:10.1016/0924-9338(96)89148-6.
^ Hart, D.; S.W. Smith (2007). "Retrospective Validation of a Clinical Decision Rule to Safely Rule Out Subarachnoid Hemorrhage in Emergency Department Headache Patients". Annals of Emergency Medicine50 (3): S102-S103. doi:10.1016/j.annemergmed.2007.06.388.
^ Heyden, Y. Vander et al.; S.W. Smith (2001). "Guidance for robustness/ruggedness tests in method validation". Journal of Pharmaceutical and Biomedical Analysis (Elsevier) 24 (5 - 6): 723 - 753. doi:10.1016/S0731-7085(00)00529-X.
^ Ermer, Joachim; John H. McB. Miller (2005). Method Validation in Pharmaceutical Analysis: A Guide to best Practice. Wiley-VCH, 418. ISBN 3527312552.
^ Ocampo, Arlene et al. (2007). "Current challenges for FDA-regulated bioanalytical laboratories for human (BA/BE) studies. Part I: defining the appropriate compliance standards - application of the principles of FDA GLP and FDA GMP to bioanalytical laboratories". The Quality Assurance Journal (John Wiley & Sons) 11 (1): 3 - 15. doi:10.1002/qaj.399.
^ Haboudane, Driss et al. (2004). "Hyperspectral vegetation indices and novel algorithms for predicting green LAI of crop canopies: Modeling and validation in the context of precision agriculture". Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (Elsevier) 90 (3): 337 - 352. doi:10.1016/j.rse.2003.12.013.