Rational Team Concert and the future of ClearCase/UCM

Now IBM Rational Team Concert (RTC) supports Software Configuration Management (SCM) and build management, I am wondering how this would affect the future of ClearCase and UCM. Will it replace ClearCase? Will it complement ClearCase? Will RTC only be for small organizations, just like UCM started?

Number of users

Currently RTC is suited for no more than 250 users. This number is significantly lower than the maximum number of users that ClearCase/UCM can deal with. But how will this change in the future.
The Team Concert application may be technically improved to support more than 250 users. However, RTC is particularly suited for Agile developments and in my opinion a team of 250 users is about the maximum for an Agile project. A team in SCRUM should not exceed 10 people because stand-up meetings will take too long and people are not made to listen and remember the daily stories of more than 10 people. Having a SCRUM-of-SCRUMs of 10 people means that you cannot bundle more than 10 teams of 10 people, which makes 100 people.
Give or take a little larger teams, or smaller teams and 3-level SCRUM, I cannot image to exceed 250 people significantly.

RTC replacing ClearCase/UCM and Telelogic?

IBM now supports 3 SCM solutions: Rational ClearCase, Rational Team Concert and Telelogic Synergy. Given the number of users, RTC cannot replace ClearCase.
The most obvious direction is to use ClearCase or Synergy as the enterprise backbone for SCM data. All major deliveries (e.g. major milestones, releases) will be kept by the ClearCase database. RTC will then become the user's front-end to SCM.

The way this is going to work is through the connectors of RTC. RTC will combine SCM, build management and work item management, which more or less bundles the management of activities and their results. The data is kept in a RTC repository, the Jazz Team Server, using a rich data model; more rich than ClearCase or Synergy needs. Through the connectors, the rich data is synchronized with the enterprise SCM backbone (ClearCase / Synergy).

The RTC repository (Jazz Team Server) will contain only the data that is needed for the project, no more, no less. The project is started by extracting (through the connector) the needed data from ClearCase/UCM. Since UCM supports streams and baselines similar the RTC, there is an easy match to the new project's stream definition, especially if the new project is a successor of an old project that delivered the data from RTC to ClearCase/UCM in the first place.
When the project is run it is synchronized with the ClearCase/UCM backbone system through the connector, at the events as defined for the company (e.g. hourly).
And finally, when the project ends the RTC environment is synced with ClearCase/UCM and the RTC environment can be removed.

This way, RTC will become the high performance, high features, integrated project front-end while ClearCase (and other enterprise systems, e.g. a planning system, a financial system, HRM systems) become the enterprise backend system for all current and historical data.

ClearCase and the Jazz Team Server

If RTC is the project's front-end and ClearCase is the enterprise SCM back-end through the connectors, then integration with any other SCM tool has the same (dis)advantages as using ClearCase as back-end SCM system. So it will be a matter of time until the competition has developed connectors. How will Rational safeguard its competitive position with ClearCase then?

I have heard that RTC and ClearCase will be integrated more directly. ClearCase (and many other Rational tools) will move towards the Jazz Team Server as the data repository. Using the data model of Rational Team Concert, there will be a more efficient synchronization between RTC and ClearCase than through connectors. This will be a significant advantage to the competition. And the competition will not move to Jazz Team Server integration because that creates a too tight dependency on IBM Rational, so they will stick to the connectors. That's pretty smart of IBM Rational!

ClearCase and Eclipse

The ClearCase Remote Client (CCRC) is implemented on Eclipse, allowing it to run in a single user environment in coexistence with other applications on Eclipse. Through Eclipse, the need for platform dependent clients (Windows, Linux) is removed since Eclipse takes care of platform dependencies.
The native ClearCase clients will move towards Eclipse. In fact, the CCRC is going to be enriched with ClearCase functions, not only to enrich the remote client functionality but ultimately to replace the native ClearCase clients. In short, CCRC will become the one and only ClearCase client.

And through the integration of all Rational products in the Eclipse environment, these applications will not only look-and-feel integrated - even if they are just separate applications within the same environment - but they also can evolve into a truely integration environment. And this is precisely what is happening in the Rational Team Concert, where different functions (not necessary different applications) are integrated into a collaborating set.

Where does it all come together?

RTC is built upon Jazz to provide the collaboration functions (instant messaging, hyperlinking, dashboard creation, etcetera). Jazz is built upon Eclipse to provide the UI and platform independence. Jazz is also built on the Jazz Team Server to unify all data, and Team Concert defines a rich data model to unify different data models.
The connectors of RTC allow synchronization with back-end applications in a controlled manner, possibly foreign applications. They also allow existing Rational tools to be connected as "foreign" applications to eventually integrate with the Jazz Team Server to high performance, high functionality integration.
The Jazz Team Server serves as intelligent cache between the back-end and the front-end.

Will everything become a plug-in?

One of the most persisting problems of software development applications for customers is the integration of applications that are not integrated by the vendor. Through the concept of connectors, external applications will be able to integrate simply by developing their own connector. However, connectors are not able to extend the data model of RTC.

So yes, all applications will be able to become a "plug-in" and fade to be background of the user experience, but only if IBM Rational allows them to - or if another application vendor will make an Team Concert-like application.

Won't IBM Rational lose ground?

IBM Rational will be the conductor of the orchestra to determine the direction of the (Rational Team) Concert. If customers want full integration, they will depend on IBM.

In addition, IBM Rational will be able to develop applications more rapidly than the competition that integrates with RTC for a number of reasons. First, they will be determine how the data model will look like and they can mold the data model to optimize integration with Rational tools. Secondly, they are much earlier than the competition because they can make use of the extended data model before it is released to the market. Thirdly, they can better integrate with or without connectors because they have all the internals information available.

And finally, through the above mentioned advantages IBM Rational will be able to bring higher quality integrations to the market at an earlier stage than the competition. The counterside of it all will be: will the customer be willing to pay for it, or rather choose for later, less functional but significantly cheaper - possibly free - alternatives. If IBM Rational will be too expensive, it is likely that an open source alternative of Rational Team Concert will emerge (just like Linux as an alternative of UNIX).