Fit-for-purpose

Ultimately, the results determined by an analytical chemist have to be good enough, accurate enough, to allow the proper use of them. The concept of fit for purpose sums up what is required. Remember no one wants analytical chemistry for its own sake. They want to know if they can eat the food, drink the water, invest in the gold mine. The quality of the analytical chemistry needs to be sufficient to answer the question. A litmus paper test for pH could well have an uncertainty of 2 pH units, but if the interest is only to find out if the solution is acidic, then litmus paper is entirely fit for purpose, and the use of a carefully calibrated pH meter would be overkill. 

The United Kingdom Laboratory of the Government Chemist has proposed six principles of valid analytical measurement (YAM)  

The methods of data analysis described in this book will be of use in fulfilling each of these principles. Without a proper understanding of the statistics of data an analyst cannot hope to deliver results that are fit for purpose.  

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Maybe we should regard the efforts of Commission V of the IIW in the seventies and eighties, to establish Fitness For Purpose approaehes, as being far ahead of their time. Fihiess For Purpose criteria cannot exist in combination with NDT methods that simply do not provide the necessary information. But nowadays, we are in a much more comfortable situation. 

Whether or not you have submitted a formal tender, any offer you make in response to a requirement is a kind of tender. Where a customer s needs are stated and you offer your product, you are implying that it responds to your customer s stated needs. You need to ensure that your tender is compatible with your customer s needs otherwise the customer may claim you have sold a product that is not fit for purpose . If the product or service you offer is in any way different than the requirement, you need to point this out to your customer in your tender or in negotiations and reach agreement. Always record the differences in the contract. Don t rely on verbal agreements as they can be conveniently forgotten when it suits one party or the other. 

Expressing the design output in terms that can be verified and validated means that the requirements for the product or service need to be defined and documented. The design input requirements should have been expressed in a way that would allow a number of possible solutions. The design output requirements should therefore be expressed as all the inherent features and characteristics of the design that reflect a product which will satisfy these requirements. Hence it should fulfill the stated or implied needs, i.e. be fit for purpose. 

However, the source of MU water for higher pressure steam-raising plants is important because it is generally the case that no matter the origin of the water, it will not be entirely suitable for the purpose and some form of water conditioning will be required. This conditioning requirement necessitates the provision of a (pre-boiler section) water pretreatment plant system (external treatment/external conditioning) to render the water fit for purpose. 

The final element which regulations address is quality. Safety and fitness for purpose, as discussed above, are two of the characteristics that you would associate with a quality product. However, these characteristics alone would not describe a quality product. For any product or service to be considered quality you would also expect it to be reliable and consistent. Additionally in the context of medical products, quality means a requirement to demonstrate conformance to agreed specifications or applicable standards for content, purity and stability. Many organisations, from manufacturers to service providers, voluntarily apply quality assurance systems in order to more effectively meet their customers needs on a consistent basis. However,... 

In those cases where there are any doubts about the feasibility of producing a sufficiently homogeneous and stable reference material, a feasibility study might be needed. For this study, an extra amount of material is needed. Questions regarding the best way of preparing the sample, the stability of the material, or the fitness for purpose might justify the inclusion of a feasibility study in the project. In the BCR projects, it is common practice to have a feasibility study, which usually has as the sole purpose of assessing the performance of the laboratories in the collaborative study in relation to the certification of the reference material. The feasibility study allows the participants to fine-tune their equipment, their methods, and their procedures in view of the characterization measurements. In each of these cases, a considerable extra number of samples is needed. 

This Section describes one of the first successful attempts, by a multi national project team funded by the European Commission s DC XII, to produce and certify a microbiological CRM that is both fit for purpose and meets the requirements of the ISO Guides. The first results are two bacterial strains, Enterococcus faecium (CRM 506) and Salmonella typhimurium (CRM 507) (fanning et al. 1995). Both are available as part of the EU BCR range of CRMs. 

LGC - VAM Publications (i) The Fitness for Purpose of Analytical Methods, A Laboratory Guide to Method Validation and Related Topics, (2) Practical Statistics for the Analytical Scientist A Bench Guide By TJ Farrant, (3) Trace Analysis A structured Approach to Obtaining Reliable Results By E Pritchard, (4) Quantifying Uncertainty in Analytical Measurement, and (5) Quality in the Analytical Chemistry Laboratory. LGC/RSC Publications, London, England. 

J.D. MacNeU, J. Patterson, and V. Martz, Validation of analytical methods - proving your method is fit for purpose, in Principles and Practices of Method Vahdation, ed. A. Flajgelj and A. Ambrus, MPG Books, Bodmin, pp. 100-107 (2000). 

In this article, an analytical method is defined as series of procedures from receipt of a sample to final determination of the residue. Validation is the process of verifying that a method is fit for purpose. Typically, validation follows completion of the development of a method. Validated analytical data are essential for monitoring of pesticide residues and control of legal residue limits. Analysts must provide information to demonstrate that a method intended for these purposes is capable of providing adequate specificity, accuracy and precision, at relevant analyte concentrations and in all matrices analyzed. 

Numerous applications for biocides have been found in fields as diverse as ethical pharmaceuticals and cat litter products. The aim of this Cl book is two-fold to provide a comprehensive guide to the use of biocides across a range of applications and to aid in the selection of a biocide that is "fit for purpose". It covers a Cl cross-section of traditional measures, novel ideas and innovative developments, as well as addressing the biocides market, the political outlook and future trends of biocide use. 

Fitness for purpose (food/water contact materials, toys, medical)... 

EURACHEM (1995) Quantifying uncertainty in analytical measurement. Teddington EURACHEM (1998) The fitness for purpose of analytical methods. Teddington... 

Take a moment to survey the spectrum and ask yourself if it is fit for purpose Of course, if you have run it yourself, then it should be fine but this may not always be so with walk-up systems. Is the line shape and resolution up to standard Has the spectrum been phased correctly Is the vertical scale well adjusted so that you can see the tops of all the peaks (except perhaps, obvious... 

Not part of Consumer Protection Act but applied by UK industry as a voluntary code of practice. This will be incorporated into the relevant British Standard and used to define "fitness for purpose."... 

To ensure that analytical results are fit for purpose, there has to be a discussion with the customer before the analysis is started. You must remember that a customer who is a member of your laboratory is just as important as the customer from outside your organization. 

Analytical measurements should be made using methods and equipment which have been tested to ensure they are fit for purpose. 

This chapter outlines the means by which results which are fit for purpose are achieved. There are examples of how unreliable results can affect all of our lives. It explains some of the nomenclature encountered in quality management and why a quality management system is important. There is a brief description of the international standards that are applicable to a chemical analysis laboratory. 

Ultimately, the choice of method will depend on several factors. Above all, fitness for purpose must be uppermost in your mind. Will the method you have selected be adequate for the decision you and/or your customer has to take when the result is available ... 

It is clear that both need to be fit for purpose . In spite of care in selecting the techniques, things can still go wrong and incorrect results produced. 

If no method exists for the analysis required, then either an existing method has to be adapted or a new method developed. The adapted or developed method will need to be optimized and the controls required identified, hence ensuring that the method can be used routinely in the laboratory. Evidence is then collected so as to demonstrate that the method is fit for purpose . The extent of validation, i.e. the amount of effort that needs to be applied, depends on the details of the problem and the information already available. Figure 4.3 indicates an approach that can be used to decide on the extent of validation required. The answer to DQ 4.2 has already mentioned that the customer may request a particular method. If... 

The validation is therefore not complete until there is a detailed description of the method and records of the validation study. A responsible person needs to sign that the method meets the requirements, i.e. it is fit for purpose . The documentation facilitates the consistent application of the method, within its scope and defined performance parameters. This, in turn, helps ensure that when the method is applied in different laboratories or at different times, the measurand is the same and that the measurement results are comparable. Documentation is also required for quality assurance, regulatory and contractual purposes. 

This section has a twofold purpose. First, it is intended to enable minor changes to be made to the text of the method without the need for a full revision and reprint of the method. Secondly, it is recommended that every method should be reviewed periodically for fitness for purpose and the summary serves as a record that this has been done. The summary typically would be located at the front of the method, just inside the front cover. 

What is essential in establishing traceability is that the measurand is specified unambiguously. This may be, e.g. in terms of extractable cadmium from soil by using a named acid mix or the concentration of a metal in a particular oxidation state, e.g. Fe(n) or Fe(m). The units used to report the result should also be known and acceptable SI units are preferred. The method used will be validated and if used in accordance with the written procedures should produce results that are fit for purpose . The class of glassware to be used will be specified in the method procedure, e.g. Class A pipettes and volumetric flasks, as these are manufactured to a specified tolerance. Instruments will be regularly calibrated and their performance verified daily. In terms of the chemicals used, these will... 

All equipment has limitations, for example, the amount of a substance it can detect or the accuracy with which it can make a measurement. If you attempt to make the equipment perform beyond its capabilities, it does not matter how carefully the equipment is operated, it will not be possible to get meaningful results. In terms of a particular instrument, fitness for purpose is interpreted as having appropriate performance capability to do the work required. This applies to all equipment, large or small. For example, a stirrer needs to perform the intended task satisfactorily while remaining essentially inert. There is a formal process for assessing the suitability of equipment to perform a given task - this is called Equipment Qualification or Equipment Validation. This is dealt with in Section 5.6.3. 

In this case, the target range is chosen to ensure that laboratories obtaining a satisfactory score are producing results that are fit for a particular purpose. The chosen value is therefore related directly to a fitness for purpose statement, which may be derived from a legislative requirement. 

The target range can also be set at a value that corresponds to the level of performance that the scheme organizer, and the participants in the scheme, would like laboratories to be able to achieve. This is sometimes referred to as setting the target range by perception and is equivalent to using a fitness for purpose statement. 

It is not always easy or possible to set a target range based on fitness for purpose criteria and so in some cases alternative approaches are used. 

The target range for this proficiency testing scheme has been set at 0.03 %abv, based on fitness for purpose criteria. Using an assigned value (X) of 40.04 %abv... 

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