This has potential to support aircraft engine inspectors to guide their maintenance tasks, as well as investigators to identify the root-causes after a defect may lead to severe damage. Further, the findings of the induction borescope inspection at the MRO shop determines whether or not to commit to a costly disassembly of the engine. The maintenance of aero engines is intricate and time-consuming and even one maintenance episode may be an appreciable proportion of the engine list price .

As you go deeper into a taxonomy, the concepts become more specific . Another common area of confusion regards the difference between a taxonomy, a thesaurus, an Ontology, and a knowledge graph. They are all forms of metadata used for classification. They can all be represented as graphs in which the nodes are concepts and the edges are different kinds of relationships between these concepts. Facets, which allow users to apply multiple filters simultaneously, are based on faceted taxonomies. Facets allow users to get extremely specific with their information needs without tediously browsing through a deep navigation tree.

A Feature Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for future research directions and describes possible research applications. They are hierarchical lists with root causes, failure signs, and other defect-related elements. Some find it easier to think of them as classifications. The latest articles about interface usability, website design, and UX research from the Nielsen Norman Group. The long-term usefulness of the taxonomy depends on having regular reviews to add, rename, merge, or remove terms, and also to spot-check examples of how content has been tagged to ensure that the taxonomy is used properly.

Supplementary Materials

The physical action phase is about executing tasks by manipulating user interface objects, while the assessment phase includes user feedback and the user’s ability to assess the effectiveness of physical actions outcome. Finally, we assigned the causes to the resulting defects. This was challenging as causes can lead to one or multiple defects, resulting in a complex intertwined network. The goal was to present it in an integrated and coherent manner.

Moreover, the ontology cannot express logical gates, which is relevant to define whether one or multiple causes or conditions must be present before a damage may occur. It is therefore not possible to differentiate between a cause that lead to a defect on its own, and contribution factors that only accelerate the defect development but cannot cause the defect independently. First, the depth of causation is limited to the second level as shown in Figure 3. This is also the reason why the links in the ontology between causes and defects were only displayed to the second level of causation . The third level is only representative as there are, for example, hundreds of objects that may cause a dent.

In the following paragraphs we summarize the rationale for our revisions. At the same time, we also used the card-sorting technique to group defects that could not be classified using UPT. We looked for commonalities and similarities to further group the defects within each category as well as across categories. The software development process, especially when it comes to complex projects, suggests multiple layers of such factors as customer demands, devel… The hierarchical system of categories designed to assist in the classification of defects.

A taxonomy can be either hierarchical or faceted. A faceted taxonomy is made up of several hierarchical , distinct taxonomies that work together to describe different aspects of the same resource. Taxonomies revolve around parent-child relationships between concepts.

Moreover, it proposes a method to link potential causes to the defects, and show the inter-relationships and cascade effects. The main audience to whom the work is directed are MRO service providers, but the results may also be applicable to engine developers and accident investigators. Andre et al. have expanded the UPT to include other usability engineering support methods and tools. By adapting and extending Norman’s theory of action model, they developed Usability Action Framework that used different interaction styles. For example, the high-level planning and translation phase contains all cognitive actions for users to understand the user work goals, task and intentions, and how to perform them with physical actions.

In addition to taxonomies that suggest the types of defects that may occur, always evaluate the impact on the customer and ultimately on your organization if they do occur. Defects that have low impact may not be worth tracking down and repairing. This paper defines engine blade defects, assigns root-causes, shows causal links and cascade effects and provides a taxonomy system. Defect types were identified from the literature and maintenance manuals, and categorised into Surface Damage, Wear, Material Separation and Material Deformation. A second categorisation identified potential causes of Impact, Environmental causes, Operational causes, Poor maintenance, Poor manufacturing and Fatigue.

Improving cross-project defect prediction with weighted software modules via transfer learning

Each of them is valid and used for different purposes. For example, for investigators of an incident or accident, it is essential to know the root-cause and how such an event can be prevented in the future. In contrast, an MRO facility is interested in the location within the engine where the defect is most likely to occur, to identify parts needing to be replaced and therefore to be purchased.

Our observations are that many open source usability defect reports have defect descriptions that contain a lack of contextual information, particularly on the user-task. As a result, when using UPT to classify usability defects, we have to make many assumptions and a self-judgement about the task performed by the users that lead to the problems. We believe UPT is useful for usability evaluators to assess the usability defects during usability evaluation with the presence of users, but not to classify defects by just reviewing the usability defect description.

Wang, W.; Liu, X.; Luo, Y.; Wang, X.; Xu, Z.J.C.E. Study of ontology and application for emergency event model. A crack is often an expansion of a pre-existing defect such as a nick, scratch or gouge. A number of possible lines of further research are suggested. Find support for a specific problem in the support section of our website. Feature papers are submitted upon individual invitation or recommendation by the scientific editors and must receive positive feedback from the reviewers.

The purpose of this research was to identify defects on aero engine blades, assign possible root-causes, show their inter-relationships, causal links and cascade effects and present it in a coherent manner. Engine blades and vanes are the most expensive and highly stressed parts, and thus the most rejected parts during engine maintenance . Engine vanes are similar to blades to the extent that both have an airfoil design and are made out of similar materials and coatings . Thus, the defects found on engine vanes are identical to those on blades. For simplification, hereinafter the term ‘blade’ is used for both blades in the compressor and turbine section, and for turbine vanes.

This work makes several novel contributions. First, it provides a single comprehensive collection of engine blade defects. This may support standardisation and enable ease of communication by providing a defect definition and description. This list summarises different terminologies for the same defect and provides a German translation.

Scrum Development Team: roles, responsibilities, and processes in one guide

I tend to use IEEE definitions when using things formally, just because that’s what I’m familiar with. Your “bug” is actually what is formally called a fault. However, that fault was injected by a mistake in an earlier process. In your example, the specification contained a mistake. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of http://potihonku.ru/mennesker227.htm some of the most exciting work published in the various research areas of the journal. A review of the origins of mites is followed swiftly by a fascinating discussion of their complex and sometimes confusing taxonomy.

• Testing can be done without the use of taxonomies or with a taxonomy to guide the design of test cases.
• The physical action phase is about executing tasks by manipulating user interface objects, while the assessment phase includes user feedback and the user’s ability to assess the effectiveness of physical actions outcome.
• Taxonomies are what information-science professionals call controlled vocabularies— planned, prescriptive ways of adding descriptive metadata to content so that it can be retrieved effectively.
• However, that fault was injected by a mistake in an earlier process.
• Additionally, the use of pre-defined values for some of the attributes may introduce selection bias and users are likely to select incorrect values.

The term is derived from the Greek taxis (“arrangement”) and nomos (“law”). Taxonomy is, therefore, the methodology and principles of systematic botany and zoology and sets up arrangements of the kinds of plants and animals in hierarchies of superior and subordinate groups. Among biologists the Linnaean system of binomial nomenclature, created by Swedish naturalist Carolus Linnaeus in the 1750s, is internationally accepted. Decide on the preferred term and nonpreferred variants for each concept. The best practice is to choose a user-friendly term as your preferred term and link internal business jargon or more technical language as nonpreferred synonyms. Look to see if there is a standard taxonomy for your industry or domain available first.

Support

The exceptions are maintenance tools and equipment that are left behind during maintenance tasks, which are instead listed in the ‘Poor Maintenance’ section. Next, we evaluated different classification systems and categorised the defects based on the type of damage. The defect categories include ‘Surface Damage, Wear, Material Separation and Material Deformation’. No taxonomy has a one-fits-all property – it’s likely to require some modifications to fit the product your testing for.

Software Engineering Stack Exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. Defect taxonomies should be frequently updated. If they are used in similar circumstances, an additional benefit to having a taxonomy is that later on, test cases can be built on them. Dicotyledonous ones in 1703, recognized the true affinities of the whales, and gave a workable definition of the species concept, which had already become the basic unit of biological classification. He tempered the Aristotelian logic of classification with empirical observation. Their knowledge, however, is according to need, and such people generalize only rarely.

They typically apply a reliability-centred maintenance methodology, whereby they seek to identify and manage failures to preserve the technical functionality, and hence safety and airworthiness of the engine. Most defects that can lead to failures are detected during maintenance inspection before any negative effects appear on flight operations. Early failure detection ensures low engine failure rates during flight operation . The maintenance inspection is primarily by visual means . The most rejected engine parts are blades and vanes from compressor and turbine sections .

This may support the inspection task by guiding the worker during the inspection process, and help prioritise such inspections as may be necessary to determine the health of the engine. Fourth, we applied an ontology to link the potential causes to the defects and show the inter-relations, causal links and cascade effects. This represented the complex relations and interactions between defects, causes and temporal progression of events. This has potential to support aircraft engine inspectors to guide their maintenance tasks, as well as investigators to identify the root-causes after a defect leads to severe damage. Blade defects are often caused by occurrence and a combination of different damage mechanisms, such as fatigue, creep, corrosion, erosion, sulfidation, foreign object damage and vibration . For example, a foreign object impact, such as a bird, can cause a nick that breaks the material flow and concentrates stresses, which initiates the development of a crack.

Reporting Usability Defects: a Systematic Literature Review

However, we do not claim that the list is perfectly comprehensive, nor entirely validated. It merely represents what is commonly known about the cause–defect relationship. While it may be ideal that each of these relationships be verified, that would require new research and a changed level of record-keeping in the industry . Nor have we addressed the other ‘Damage Attributes’ identified above. Nonetheless, in principle, such additional data could be added to the table as additional fields. We propose that potential causes vary for different types of defects.

Once the usability defects have been fixed, the developers record four attributes in Post-CUP. For example, technical information about defect removal activity, failure qualifier, expected phase, and frequency are difficult to obtain, especially for those who have limited usability-technical knowledge. From a software engineering perspective, cause-effect classification models provide a deeper understanding of a software problem. To the best of our knowledge, only one usability cause-effect classification currently exists.