What is OSLC?

Open Services for Lifecycle Collaboration (OSLC) is an open community creating specifications for integrating tools. These specifications allow conforming independent software and product lifecycle tools to integrate their data and workflows in support of end-to-end lifecycle processes. Examples of lifecycle tools in software development include defect tracking tools, requirements management tools and test management tools. There are many more examples in software and product development and more still in “IT operations” (sometimes called service management) where deployed applications are managed.

The OSLC community is organized into workgroups that address integration scenarios for individual topics such a change management, test management, requirements management and configuration management. These topics that have OSLC workgroups and specifications are called “domains” in OSLC. Each workgroup explores integration scenarios for a given lifecycle topic and specifies a common vocabulary for the lifecycle artifacts needed to support the scenarios.

To ensure coherence and integration across these domains, each workgroup builds on the concepts and rules defined in the OSLC Core specification, which is produced by the Core workgroup. The OSLC Core specifies the primary integration techniques for integrating lifecycle tools. This consists mostly of standard rules and patterns for using HTTP and RDF that all the domain workgroups must adopt in their specifications. The Core Specification is not intended to be used by itself. Since there is no such thing as a generic lifecycle tool – every tool is specialized to one or more domains such as requirements, defect tracking, testing and so on – the Core Specification in conjunction with one or more of the OSLC domain specifications describe the OSLC protocols offered by a domain tool.

The goal of OSLC is to create specifications for interactions between tools. OSLC is not trying to standardize the behavior or capability of any tool or class of tool, like a test tool or a requirements management tool. OSLC specifies a minimum amount of protocol and a small number of resource types to allow two such tools to work together relatively seamlessly. Even within a particular resource types specified by an OSLC workgroup, the goal is to define only properties that are valuable for integration, not all the properties that might be present in a particular tool’s resources. OSLC also tries to accommodate a wide variety of implementation technologies, and be equally relevant to both existing tools and to newly-built ones.

OSLC Technical Foundation

OSLC is based on the W3C Linked Data. Here is a reminder of the 4 rules of linked data, authored by Tim Berners-Lee and documented on the W3C web site: http://www.w3.org/DesignIssues/LinkedData.html.

  1. Use URIs as names for things
  2. Use HTTP URIs so that people can look up those names
  3. When someone looks up a URI, provide useful information, using the standards (RDF*, SPARQL)
  4. Include links to other URIs. so that they can discover more things. (sic)

 

In OSLC, each artifact in the lifecycle – for example, a requirement, defect, test case, source file, or development plan and so on – is an HTTP> resource that is manipulated using the standard methods of the HTTP specification (GET, PUT, POST, DELETE).

Following the third rule of linked data, each resource has an RDF representation – OSLC mandates RDF/XML, which is the most widely adopted RDF notation - but can have representations in other formats, like JSON or HTML.

The OSLC Core specification defines a number of simple usage patterns of HTTP and RDF and a small number of resource types that help tools integrate and make the lifecycle work. The OSLC domain workgroups specify additional resource types specific to their lifecycle domain, but do not add new protocol.

Primary OSLC integration techniques

OSLC offers two primary techniques for integrating tools – “Linking data via HTTP” and “Linking Data via HTML User Interface”. Both of these techniques build on the HTTP and RDF foundation of OSLC.

Linking data via HTTP

OSLC specifies a common tool protocol for creating, retrieving, updating and deleting (CRUD) lifecycle data based on internet standards like HTTP and RDF using the Linked Data model. This protocol can be used by any tool or other programmatic client to talk to any other tool that implements the specifications. Linking is achieved by embedding the HTTP URL of one resource in the representation of another.

Linking Data via HTML User Interface

OSLC specifies a protocol that allows a tool or other client to cause a fragment of the web user interface of another tool to be displayed, allowing a human user to link to a new or existing resource in the other tool or see a preview of information about a resource in another tool. This enables a tool or other client to exploit existing user interface and business logic in other tools when integrating information and process steps. In some circumstances this is more efficient and offers more user function than implementing a new user interface and then integrating via an HTTP CRUD protocol.

Both of these techniques are described in this primer.