The present invention provides a method and system for multi-threaded processing that is an improvement over conventional systems. The system of the present invention comprises multiple threads of execution, multiple apartments, shared data, and a concurrency management component. The threads of execution run independently and each occupy one apartment. The apartments contain objects that have methods to perform operations. The shared data contains data that is accessible by all threads within the process. The concurrency management mechanism performs processing so that the multiple threads can execute concurrently in a reliable and robust manner. In an alternative system of the present invention, the threads are separate from the apartments and the threads execute within the apartments to perform processing. After performing the processing, the thread exits the apartment so that the apartment may be occupied by another thread.