This task involved construction of a hierarchical taxonomy for standardization of technical issue descriptions. For this purpose, we used several existing technical issue taxonomies used by different business analytics applications and teams. In parallel, we performed an Exploratory Data Analysis (EDA) of case logs to understand the detailed requirements of taxonomy including capturing technical issue semantics, nomenclature, and minimizing duplication and the number of categories (see Exploratory data analysis). We opted for three-tier label hierarchy for describing each technical issue, where the:

• First level (known as T1) is the least granular level, which represents an overall issue category (for example, boot related)
• Second level represents subissue types within first level (known as T2)
• Third tier represents the most granular and specific issue information (known T3).

For example, consider the following T1-T2-T3 label:  

Here, T1 = [Power] is the least granular level of information and under power; T2 = [AC Adapter], and T3 = [AC Adapter Noise Issue] is most granular level of information provided.

The combination of the T1-T2-T3 label hierarchy can succinctly describe over 85 percent of frequently occurring technical issues. In addition to deriving labels with the aid of EDA, we liaised with the domain experts to consolidate several exiting taxonomies and curate a set of all-encompassing T1-T2-T3 labels.

Furthermore, a set of syntactic rules were established on how to format each T1-T2-T3 label. These rules ensure future conformity and standardization as new labels are added. Example formatting rules include:

• Use title case and capitalize all abbreviations and acronyms
• Use the pipe “|” character as the delimiter for each label component (so that commas and hyphens can be preserved in a label component if required)
• Add spaces around the pipe | delimiter.
• Remove spaces around the “/”, “-“and “:” characters.
• Replace “and” with the ampersand “&”, to make the label shorter.

Table 1.      Example T1-T2-T3 Labels for describing consumer technical Issues

A major concern of having a fixed set of T1-T2-T3 labels for describing technical issues is that novel and unseen issues may not be represented or captured by downstream ML models. To address this concern, a label governance process has been established that ensures new standardized labels are introduced periodically while minimizing duplication with respect to existing labels. Another concern is the growing number of labels over time with the new additions, and therefore the governance process also includes steps to invalidate or remove infrequent or outdated labels.