Workflow management systems support the eficient, largely automated execution of business processes. However; using a workflow management system typically requires implementing the application's control flow exclusively by the workflow management system. This approach is powerful if the control flow is specified and implemented from scratch, but it has severe drawbacks if a workflow management system is to be integrated within environments with existing solutions for implementing control flow. Usually, the existing solutions are too complex to be substituted by the workflow management system at once. Hence, the workflow management system must support an incremental integration, i.e. the reuse of existing implementations of control flow as well as their incremental substitution.Extending the workflow management system's functionality according to future application needs, e.g. by worklist and history management, must also be possible. In particular at the beginning of an incremental integration process, only a limited amount of a workflow management system's functionality is actually exploited by the workflow application. Later on, as the integration proceeds, more advanced requirements arise and demand the customization of the workfow management system to the evolving application needs.In this paper; we present the architecture and implementation of a light-weight workflow management system, coined Mentor-lite, which aims to overcome the above mentioned shortcomings of conventional workflow management systems. Mentor-lite supports an easy integration of workflow functionality into an existing environment, and can be tailored to specific workflow application needs.