A test method is a method for a test in science or engineering , such as a physical test , chemical test , or statistical test . It is a definitive procedure that produces a test result. In order to ensure accurate and relevant test results, a test method should be "explicit, unambiguous, and experimentally feasible.", as well as effective and reproducible.
17-505: The American Association of State Highway and Transportation Officials ( AASHTO ) is a standards setting body which publishes specifications, test protocols , and guidelines that are used in highway design and construction throughout the United States. Despite its name, the association represents not only highways but air, rail, water, and public transportation as well. Although AASHTO sets transportation standards and policy for
34-458: A broadened scope to cover all modes of transportation, although most of its activities are still specific to highways. While AASHTO is not a government body, it does possess quasi-governmental powers in the sense that the organizations that supply its members customarily obey most AASHTO decisions. The voting membership of AASHTO consists of the Department of Transportation of each state in
51-408: A given sample, product, process, or service. The purpose of testing involves a prior determination of expected observation and a comparison of that expectation to what one actually observes. The results of testing can be qualitative (yes/no), quantitative (a measured value), or categorical and can be derived from personal observation or the output of a precision measuring instrument . Usually
68-486: A test result is used to predict or imply suitability for a certain purpose. For example, if a manufactured item has several components, test methods may have several levels of connections: These connections or correlations may be based on published literature, engineering studies, or formal programs such as quality function deployment . Validation of the suitability of the test method is often required. Quality management systems usually require full documentation of
85-430: Is a major component of quality control, where physical product is examined visually (or the end results of a service are analyzed). Product inspectors will be provided with lists and descriptions of unacceptable product defects such as cracks or surface blemishes for example. Early stone tools such as anvils had no holes and were not designed as interchangeable parts . Mass production established processes for
102-566: Is a tendency for individual consultants and organizations to name their own unique approaches to quality control—a few of these have ended up in widespread use: In project management , quality control requires the project manager and/or the project team to inspect the accomplished work to ensure its alignment with the project scope. In practice, projects typically have a dedicated quality control team which focuses on this area. Test method A test can be considered an observation or experiment that determines one or more characteristics of
119-431: Is common for a physical property to be strongly affected by the precise method of testing or measuring that property. As such, fully documenting experiments and measurements while providing needed documentation and descriptions of specifications , contracts , and test methods is vital. Using a standardized test method, perhaps published by a respected standards organization , is a good place to start. Sometimes it
136-484: Is more useful to modify an existing test method or to develop a new one, though such home-grown test methods should be validated and, in certain cases, demonstrate technical equivalency to primary, standardized methods. Again, documentation and full disclosure are necessary. A well-written test method is important. However, even more important is choosing a method of measuring the correct property or characteristic. Not all tests and measurements are equally useful: usually
153-454: Is often required to submit test results to state DOTs. For example, a contract for the construction of a highway bridge may require a minimum compressive strength for the concrete used. The contract will specify AASHTO Test Designation T 22, "Compressive Strength of Cylindrical Concrete Specimens," as the means of determining compressive strength. The laboratory performing T 22 will be required to be accredited in that test. AASHTO coordinates
170-512: The United States as a whole, AASHTO is not an agency of the federal government; rather it is an organization of the states themselves. Policies of AASHTO are not federal laws or policies, but rather are ways to coordinate state laws and policies in the field of transportation. The American Association of State Highway Officials (AASHO) was founded on December 12, 1914. Its name was changed to American Association of State Highway and Transportation Officials on November 13, 1973. The name change reflects
187-550: The United States, as well as those of Puerto Rico and the District of Columbia . The United States Department of Transportation has a non-voting associate membership. Some noteworthy AASHTO publications are: In addition to its publications, AASHTO performs or cooperates in research projects. One such project is the AASHTO Road Test , which is a primary source of data used when considering transport policies and
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#1732773256424204-444: The creation of parts and system with identical dimensions and design, but these processes are not uniform and hence some customers were unsatisfied with the result. Quality control separates the act of testing products to uncover defects from the decision to allow or deny product release, which may be determined by fiscal constraints. For contract work, particularly work awarded by government agencies, quality control issues are among
221-479: The limits. Quality was thus precisely defined using devices such as plug gauges and ring gauges . However, this did not address the problem of defective items; recycling or disposing of the waste adds to the cost of production, as does trying to reduce the defect rate. Various methods have been proposed to prioritize quality control issues and determine whether to leave them unaddressed or use quality assurance techniques to improve and stabilize production. There
238-506: The numbering of Interstate Highways , U.S. Highways , and U.S. Bicycle Routes . Current and withdrawn AASHTO standards include: Quality control Quality control ( QC ) is a process by which entities review the quality of all factors involved in production . ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements". This approach places emphasis on three aspects (enshrined in standards such as ISO 9001): Inspection
255-751: The structural design of roads. Much of AASHTO's current research is performed by the National Cooperative Highway Research Program (NCHRP) which is administered by the Transportation Research Board (TRB), a division of the National Academy of Sciences, Engineering, and Medicine . AASHTO re:source, formerly the AASHTO Materials Reference Laboratory (AMRL), accredits laboratories. Accreditation
272-583: The test result is the dependent variable , the measured response based on the particular conditions of the test or the level of the independent variable . Some tests, however, may involve changing the independent variable to determine the level at which a certain response occurs: in this case, the test result is the independent variable. In software development , engineering , science , manufacturing , and business , its developers, researchers, manufacturers, and related personnel must understand and agree upon methods of obtaining data and making measurements . It
289-440: The top reasons for not renewing a contract. The simplest form of quality control was a sketch of the desired item. If the sketch did not match the item, it was rejected, in a simple Go/no go procedure. However, manufacturers soon found it was difficult and costly to make parts be exactly like their depiction; hence around 1840 tolerance limits were introduced, wherein a design would function if its parts were measured to be within
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