The artifacts from distinct tools are retrieved by the Lifecycle Query Engine.
The following discusses details how the Lifecycle Query Engine uses Open Services for Lifecycle Collaboration (OSLC) to link disparate artifacts from native tools.
When users search for artifacts from any page, they leverage the linked data in the Lifecycle Query Engine index. Linked data means just that, data that is linked in other tools, such as work items with child work items, and is linked to or from a Rational Engineering Lifecycle Manager product configuration or product. For example, a product configuration called SuperCar might contain an engine child product, which contains several links to requirements, work items, design models, and test cases. The links, shown in the following image, are standard HTTP:

Representational State Transfer (REST) is a set of principles that define how Web standards, such as HTTP and URIs, are to be used. REST is the basis for Rational Engineering Lifecycle Manager's use of linked data, meaning that all artifacts have IDs, can link together, can have multiple representations, and can communicate statelessly.
The links to artifacts in the engine product come from Linked Lifecycle Data. Not only are the artifacts retrievable by the Lifecycle Query Engine index, but they are linked. In other words, the artifacts that are a part of engine are in a context, which is the product. The SuperCar product configuration might have 10 child products and each of those child products might have as many child products with dozens of work items, requirements, test cases, and design models, but all of those artifacts remain linked when retrieved from the index. When teams need to run an analysis on a product, for example, engine, not only do they see the artifacts linked to engine, but all the artifacts that have a (linked) relationship to SuperCar's artifacts.
This linking is possible through the use of OSLC, which is a standard that enables lifecycle integrations. The following image shows artifacts from different native tools linked together using OSLC and retrievable by the Lifecycle Query Engine.

Although the index is an important component of the tool, teams use the index peripherally, when they retrieve information from it through operations such as query, analysis, search, find use, history, and so forth. In other words, the index is invisible to users except as the data pool in which linked artifacts are stored and retrieved.
Aside from the operations listed in the previous paragraph, teams need to print reports on the status of artifacts. A sample report is available to display information in a basic tabular form.
To create a report with different output, such as bar charts and Gantt charts, you need Rational Publishing Engine. Rational Publishing Engine is not included with the tool; separate installation and license are required. Contact your server administrator to verify that the installation is completed and to determine the license server path that you must use to connect to the license server. If you have not already installed Rational Publishing Engine, you or your administrator must install it and verify that you can connect to the licensing server.
For Rational Publishing Engine usage information, see NEW LINK Authoring document-style reports in the Rational solution for Collaborative Lifecycle Management product documentation.
The following image shows an overview of how to use Rational Engineering Lifecycle Manager.

This image is a good overview of how teams use the tool. First, a team lead or product manager creates product configurations, organizing the child configurations, products, and artifacts in a way that makes sense for both their product and their team. Next, the team gets to work creating links to artifacts, such as work items, requirements, design models, and test cases, which further populates their product tree.
Special views and queries are created for the team. The views provide a structured, dynamic look inside the product so teams can view engineering data across the development lifecycle. For example, a V Process view shows the lifecycle of a product starting with system design, moving through software architecture, and ending with integration and testing.
The team runs operations such as search, query, find use, and analysis to find relationships between artifacts. Relationships are important when one of your products must be repaired or replaced.