Measurement data must be quickly retrievable, comparable and interpretable for different purposes and by different persons even after a long time. Companies can only achieve this by precisely documenting under which conditions (= context) the respective measurement data have been created. Conclusion 1: Transparency on test data becomes problematic, if measurement files are stored on the hard disk of a local computer or server just based on individually selected names without a detailed description.
That´s why the market offers a whole series of software tools with which this file-based storage of measurement data can be better organized.
One example of this kind of tools is National Instruments’ DataFinder. The Server Edition is a software that allows larger groups of users to find and share measurement files on servers. The measurement files are indexed for this purpose. That is, information about the files is written in a kind of catalog (= index). When searching, the software does not read the individual directories and files directly, but only the index. This simplifies and accelerates the search for measured data.
Access to the indexed data is done either directly through the National Instruments products DIAdem and LabVIEW, or via the ASAM ODS API. The latter allows ODS-compliant third-party applications to use DataFinder.
Using the so-called “DataPlugin Technology”, DataFinder can map different file formats to its internal TDM data model. TDM is derived from the ASAM ODS basic model and has minimal complexity. It provides three hierarchical levels to organize measured data: file, group and channel. For each hierarchy level, the user can define any number of attributes (additional properties). In this way, he describes the content of a measurement file. Based on the defined attributes, the user can later find the measurement file via the index of DataFinder. The software constantly updates the index, without the need for extensive IT support or specialized database expertise. Conclusion 2: DataFinder is a simple, easy-to-use solution with which users quickly and intuitively can find measurement files in a corporate network.
However, this is not enough for many companies. Especially in the context of the increasing division of work-processes in globally organized teams, the responsible persons demand solutions, which supports the work already in the test-planning phase. This is so important, because it is the basis for the long-term and person independent comparability and interpretability of test data. By means of a systematic test description, the exact technical, organizational and technological context in which certain measurement data are created is precisely documented already before the actual execution of the test. The context includes, among other things, the exact set-up state of the test item and test system as well as the description of the test procedure and the test parameters. The decisive factor here is that the test describing information is uniform, unambiguous, complete and correct across teams and locations.
Solutions such as e.g. openMDM® achieve this with the help of freely definable templates (see: How to document tests in a standardized way). They specify the attributes with which test orders, test items, measuring devices, etc. have to be described. In order to minimize time-consuming manual entries and associated input errors or gaps, inputs can be directed through defaults in selection fields. This facilitates later the systematic research in the system. Descriptive data can also be obtained from tests already available in the system or from other applications, such as test parts or measurement equipment management. To ensure the completeness, uniqueness and correctness of the meta information, the definition of mandatory or optional fields in the templates is possible and routines for the automatic generation of unique test names are available.
Conclusion 3: If a company is not only interested in finding measurement files, but also in standardizing the documentation of tests and in improving the transparency in the test environment, solutions like openMDM® are required.