Lean-Agile Traceability: Strategies and Solutions

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  • The IDE could easily know what kind of artifact we're working on (requirement, design, code, test)
  • Operations in the IDE and the version-control tool would be able broadcast "events" that know my current context (task, artifact type, operation) and could automatically create a "traceability link" in the appropriate place.
  • CASE tools and protocols like Sun's ToolTalk and HP's SoftBench tried to do this over a decade ago, but agile methods weren’t quite so formalized then or necessarily working in a TDD/TBD fashion. This is what Event-Based Traceability (EBT) is trying to help achieve. If we had the appropriate tool plug-ins (e.g., for Eclipse, or MS TeamSystem) and also used TDD/BDD with TBD in this IDE, we might just be able to get EBT for free! We may have at least come pretty close!

Search-based Traceability - Traceability without Tracing
Event-based traceability can be incredibly powerful and easy to use, as it eliminates most of the manual tracing would otherwise have to be created between artifacts and (meta)data across the multiple lifecycle phases and repositories. Within a set of phase-specific artifacts, a simple (or hi-tech) tool could be used that makes it very convenient to place linkages between items in the same artifact and/or of the same type These could include simple cross-references and item structuring/decomposition.

Search-based traceability is one of the more recent "hot topics" in traceability research. It does not require manual (or even automatic) insertion of traces between related pieces of information. Instead, it relies on smart, probabilistic and context-sensitive searching of a project's information, assets and data to dynamically infer linkages.  These are then reported, based on the specific set of search keywords used.

Event and tool-integration-based tracing may still be more convenient and effective for relating information about who did what, when, and where. Search-based traceability can be more powerful, convenient, and effective at tracing information across the lifecycle and the value-chain, though.  This is particularly true when it comes to answering questions like "Why?" and analyzing the impacts and relationships of logical items and terms across a project's knowledgebase.  This also includes less formally structured information such as project blogs, mail-lists, wikis, etc.

In its most advanced form, search-based traceability utilizes information retrieval methods such as the vector space model, semantic indexing, or probabilistic network models to dynamically generate traces at runtime. According to Jane Cleland Huang in "Just Enough Requirements Traceability":

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“The effectiveness of automated traceability is measured using the standard metrics of recall and precision, where recall measures the number of correct links that are retrieved by the tool, and precision measures the number of correct links out of the total number of retrieved links.   Numerous experiments, conducted using both experimental data sets as well as industry and government data sources, have consistently shown that when recall levels of 90-95% are targeted precision of 10-35% is generally obtainable. [Recall indicates how many of the items that should have been found, are effectively extracted. Precision indicates how many of the extracted items are correct. Usually there is a trade off of recall against precision.]This means that automated traceability methods require a human analyst to manually evaluate the candidate links returned by the tool and to filter out the incorrect ones.  Automated trace retrieval, while no silver-bullet, is increasingly recognized by industry as a potential traceability solution.  Prototype tools such as Poirot are used in industrial pilot studies.  The new Center of Excellence in Traceability has been established specifically to address these issues.”

Simple Search-based Traceability ("Just Google It!")
We needn't wait for prototypes to develop further in order to take advantage of some of the powerful ideas in search-based traceability. Available search-engines can be used today with the same kind of simple-tools previously mentioned in this article.  This is particularly true when they are used in conjunction with Wiki-webs, source code and document repositories, as well as project mail-lists and blogs.

The minimum requirement determining the relevant terms or project vocabulary that will yield meaningful search results across the project or related projects. Wiki-webs are well-suited for defining project glossaries and terms, both as definitions and also as documentation of key concepts, patterns, and domain-specific terminology. If some discipline and conventions/standards can be applied regarding the consistent communication and use of such terms and vocabulary, then using a sensible yet simple combination of all the other mechanisms above can contribute to a lean yet practical traceability solution that covers all or most of a project's traceability requirements.

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