Abstract: A method for managing design files shared by multiple users is provided. A plurality of design files are stored in a design library. A lock table is moved to a memory of a first computer when information of the lock table indicates that the design files were locked by a first process corresponding to a first user, wherein the memory is only accessible to performance of the first process. The lock table is moved from the memory to a common memory of the first computer when one design file is locked by a second process corresponding to a second user. The first and second processes are being performed in the first computer. The lock table is moved from the memory to the design library when the one design file is locked by the second process corresponding to the second user, wherein the second process is performed in a second computer.