Traceability is recognized as essential for supporting software development. However, a number of traceability issues are still open, such as link semantics formalization or standards for traceability process models. One widely accepted approach to implement traceability practices is the use of methodologies. But the information related to organization, stakeholders, product size, and quality requirements may change from one project to another. As a consequence, traceability information may differ as well. One common way to cope with this fact is the use of metamodels to underpin methodologies.
However, current traceability metamodels still have serious limitations. Concerning methodologies in general, three hierarchical layered levels have been identified: metamodel, methodology and project. Current metamodels do not often properly support this architecture, and that
results in semantic problems at the time of specifying the methodology. Most of the traceability metamodeling approaches simply provide a predefined set of concepts represented with classes, with no extension mechanisms. For instance, approaches provide extensive predefined sets of
traceability items applicable on every project, while the project attributes are domain specific and sometimes even project specific. Therefore, the customization of a methodology for a specific project is often unsatisfactory.
This thesis introduces two complementary modeling principles to overcome these limitations, which are: the metamodeling three layer hierarchy and the power-type patterns modeling principle [61, 73]. Mechanisms to extend and refine traceability metamodels are inherent to
these principles. The thesis states that, when methodologies are developed from metamodels based on these two principles, the result is a methodology well fitted to project features. Links semantics are also improved.
This thesis justifies that to approach the project specificity issue traceability metamodels must include a basic set of items. This set of basic items includes the concepts and the traceability structures designed to be extended according to the project features. For this, the proper modeling tools are strongly required: the metamodeling principles to support typing and extensibility,
together with a general and extensible integration of traceability to the software process.
This second issue is obtained from the use of the standard ISO/IEC 24744:2007 .
This thesis explains how to use these tools in practice to define a traceability metamodel named TmM (Traceability metamodel) model. TmM is applied in two case studies in which non-conventional work products and development methodology have to be considered as part of the traceability information. In the first case study, TmM has been instantiated to create the traceability methodology to support the hardware unit testing technique. In the second case study TmM is used to support specific traceability requirements originated in agile methods.