1. The Need for Requirements Management
In recent years, the growing complexity of products, shorter product development lifecycles, and increasingly stringent compliance standards have led to the increase in formalized requirements in product development and testing. As engineering projects become more ambitious, their complexity increases. This complexity is fueled by both newer technology and a trend toward engineering projects that employ development teams and contractors around the world. Formalized requirements are critical to guaranteeing the complete and correct implementation of these projects’ goals.
In addition to increasing product complexity, vendors are accelerating product development, lowering development costs, and increasing quality in hopes of gaining a competitive advantage in their markets. An effective, cost-efficient quality and testing strategy must be based on clearly defined requirements. Requirements help you specify the exact functionality of a product and guarantee that it is tested correctly and completely. Requirements management tools make the process of storing and analyzing the requirements cost-efficient.
Many companies are also faced with stringent government and industry-specific compliance requirements. Certification standards such as 21 CFR Part 11, enforced by the US Food and Drug Administration, and DO-178B, used for in-flight, onboard software for aircrafts, define guidelines for developing reliable devices and software. As companies continue to expand globally, they are faced with even more compliance requirements posed by foreign entities. Both local and foreign compliance standards rely heavily on clearly defined requirements. Furthermore, compliance standards emphasize the need to prove the links between higher-level and lower-level requirements and the implementation of requirements in the product.
2. NI Requirements Gateway
NI Requirements Gateway software is a requirements management and traceability solution that links your development and verification documents to formal requirements stored in documents and databases. NI Requirements Gateway performs coverage and impact analysis, graphically displays coverage relationships, and generates comprehensive reports. NI Requirements Gateway traces requirements defined in multiple formats such as Telelogic DOORS, IBM Rational RequisitePro, and Microsoft Word.
Figure 1. NI Requirements Gateway traces requirements in different formats, such Telelogic DOORS, IBM Rational RequisitePro, and Microsoft Word, to their implementation in multiple programming languages and test software platforms.
3. Managing Coverage Relationships with NI Requirements Gateway
The NI Requirements Gateway Configuration View is a graphical tool that makes it easy to specify coverage relationships between different project documents.
Figure 2. The NI Requirements Gateway Configuration View provides an easy-to-use graphical interface for specifying coverage relationships.
It is possible to specify covering relationships between different hierarchical levels of requirements with many different requirements management applications, such as Telelogic DOORS. However, specifying the coverage relationships between requirements and software implementation continues to be a time-consuming and error-prone process. NI Requirements Gateway defines these traceability relationships more quickly and accurately than other solutions by linking requirements directly to their implementation in programming languages such as National Instruments LabVIEW, LabWindows/CVI, MATRIXx, and test platforms such as NI TestStand, as well as common text-based programming languages. You can trace requirements to their implementation by parsing requirement coverage information documented in software. NI LabVIEW and MATRIXx use the property fields of blocks, VIs, controls, and indicators to document requirements coverage; LabWindows/CVI uses comments defined before a function; and NI TestStand uses each step or sequence’s requirements property.
4. Coverage Analysis with NI Requirements Gateway
The ultimate goal of defining requirements coverage relationships is to perform coverage and impact analyses on different elements such as specific requirements, functions, or test cases. Coverage analysis determines which elements are covering or being covered by other elements. By determining coverage relationships, you easily can identify requirements that have not been implemented or determine which requirements are being implemented by a particular function. NI Requirements Gateway includes the Coverage Analysis View, which provides a graphical interface that displays one level of covering elements and one level of covered elements for selected document elements.
5. Impact Analysis with NI Requirements Gateway
Impact analysis determines the significance of a requirements or functionality change. You can use impact analysis to trace all the different levels of requirements, functionality, or tests that would be affected by a test failure, removal of functionality, or change in requirements. The Impact Analysis View in NI Requirements Gateway displays all levels of covering elements and all levels of covered elements for selected document elements.
Figure 3. The NI Requirements Gateway Impact Analysis View shows you all levels of coverage, both up and downstream.
6. Reporting with NI Requirements Gateway
One of the many challenges faced by engineers who deal with stringent certification standards is generating reports that prove the coverage of requirements in their products or tests. NI Requirements Gateway automatically generates requirements traceability matrices and impact analysis reports using the coverage relationships specified for a project. You also can customize reports to fit the needs of your application.