Traceability of requirements

Borland Caliber - one of specialized management tools requirements maintaining traceability

The traceability allows to describe and monitor communications between different artifacts of requirements — business requirements, system requirements in different forms (including in the form of use options), and in a broad sense and development process artifacts in general.

At the same time the transitivity can be illustrated as follows: let's allow, there is a high-level business need of the customer which is traced on the function of a system which in turn is traced on use option. In this case it is obvious that change of business need can have an impact not only on directly related high-level function, but also on option of use with which function is connected. Proceeding from the same conditions, not the symmetry is treated as follows: change of business need requires the analysis of changes in the related function, at the same time the return generally is not right. Depending on specific model of requirements, trace can have and other than described properties.

Appointment

Trace of requirements is the key component of process of management of the changing requirements to a system allowing to determine the scale of impact of change in one of sources of requirements using data on communications (for example, change of the legislation, the customer's wishes) on artifacts of requirements (options of use, the specification, etc.), artifacts of the developed OS in general and, therefore, characteristics of the project in general. Thus, trace is the project risk management tool reducing the probability of exceeding of terms and the project budget at the expense of the underestimated impact of changes of requirements.

In this sense the traceability is the important property supporting determination of a system as a compromise between the competing interests of interested persons as the competition of interests is one of the main sources of changes of requirements.

Besides, trace can be used for determination of priorities of subordinate requirements (options of use, functional requirements) for a priority of the higher requirements describing business needs of the customer thereby allowing to plan the project, providing priority implementation of functionality of a system, the most important in terms of business, but not "convenient" development team for implementation.

Tools of traceability of requirements are used also for identification of the artifacts of a system which are not connected with other artifacts that allows to reveal missing "links" of development. For example, identification of options of use with which test scripts are not associated is possible.

Versions

Depending on specific implementation in methodology or the software package of management with requirements, trace can be implemented in the form of not typified communication between artifacts. In that case causes and effect relationships are monitored proceeding from type of artifacts between which trace is established.

In more complex case, communication can belong to one of the predetermined facets (for example "it is tested with the help", "follows from", "is a part"). Thus the flexibility of possible selections on communications between artifacts increases, however, it occurs due to significant complication of model. It is obvious that use of the second approach can be justified only for large projects with complex structure of requirements.

The traceability can be performed as it is exclusive between different artifacts of requirements, and between project artifacts in general. In this case traces integrate artifacts of requirements, design, implementation, testing, allowing to estimate the impact of changes of requirements not only on other artifacts of requirements, but also on architectural concepts, test scripts, the source code of a system. Thus the accuracy of impact assessment of changes of requirements of the project in general increases that allows to increase its controllability, to reduce risks of incorrect assessment of changes.

At the same time, implementation of such model requires the large-scale integration level of all components of a development environment, high methodological discipline in development team and, as a result, limits the choice of development tools and also variability of expenses, increasing at the same time costs for ensuring process. Therefore it is obvious that extent of such integration should be estimated carefully for each specific project taking into account his specific features.

Instrumental support

The traceability of requirements in the project can be maintained also without use of specialized work benches, using agreements on naming and observance by analysts of the formalized procedures of requirements management. At the same time the functionality of software of general purpose, for example, mechanisms of management of structure of the document and compound documents and also cross-references and hyperlinks of text editors, functionality of sorting and data filtering in spreadsheets, mechanisms of desktop DBMS can be used.

Such approach, however, assumes additional labor costs on maintenance of traceability and limits its applicability in the project and also sharply loses efficiency in process of increase in scale of the project.

One more approach to ensuring traceability within requirements management can consist in use different a bug - the tracking and similar systems. Such approach assumes fine tuning of the similar systems for the purposes of requirements management, at the same time the built-in mechanisms of selections and reports generation, support of worker threads of artifacts of these systems and also mechanisms of ensuring dependences can cause applicability of these means for ensuring traceability and requirements management in general. At the same time, the functionality of such systems can impose the, sometimes essential, restrictions for model of requirements, and the lack of integration with means of visual modeling and editing text artifacts of requirements also does not serve economy of labor costs on maintenance of model.

Specialized families of software products of management of lifecycle of software usually include management tools requirements with support of traceability. Distinctive feature of such means is inclusion or integration of means of import of requirements from different sources, support of visual modeling (generally on the basis of UML), close integration with means of documentation. At the same time work with traces---the analysis of changes and generation of the reporting on them (including matrixes of traces), the configured mechanisms of notifications of interested persons on changes, taking into account areas of responsibility and dependences is automated. In general, such means allow to lower labor costs on support of the mechanism of traces, at the same time providing their more flexible use. Success of their application, however, as well as many other automation equipment, depends on features of the specific project, qualities of development team, degree of a maturity of development process of software in the company in general.

Means of Borland Caliber, IBM Rational RequisitePro, (IBM) of Telelogic DOORS, Sparx Enterprise Architect, 3SL Cradle belong to the specialized management tools requirements maintaining traceability, in particular,

Within the Eclipse project creation of Open Source Requirements Framework intended for management model creation by requirements and also tools on its base is initiated.

Sources

• Open Source Requirements Framework project. ORMF Requirements model 2.0
• Wikipedia Contributors. Requirements Traceability