TCAD frameworks developed at universities ([Wong92]) like VISTA ([Pimi93], [Hala94]) additionally have to face the difficulty of a constantly changing team of programmers working on the framework and its tools, since these programmers are mostly Ph.D. students staying for typically three to five years on the project. While this may seem a long time for traditional software projects, it is fairly short compared to the long time constants involved in careful design and implementation of such a large framework and its individual components.
The VISTA project for example involves a core group of four to six
framework engineers and another eight to ten application engineers working on
framework tools. This makes up a total of at least twelve engineers who have
to interact and coordinate their ideas from the very beginning. If there are
workers on a project, there are 
communication
interfaces ([Broo82]), yielding in the order of 60 interfaces for the
VISTA project.
If a project were unmanaged, and each worker would have to interact directly with each other coworker, communication and information exchange indeed has to flow through this large number of interfaces. Managing a project now means to tackle this communication problem, which is by far non-trivial since it requires skills from the project manager that go far beyond merely technical competence.
The reasons why the VISTA project is a success lies in the apt management of those communication interfaces, the enthusiasm of the project members, constantly inspired and motivated by the project management which provided the opportunity to creative teamwork, and finally the uncompromising development and use of CASE tools inside VISTA, which make up for the homogeneous global structure and conceptual integrity of the whole project. Some of those key component CASE tools will be described in the following sections.