Silex Microsystems handles a wide range of customized MEMS components. This speech will be describing Silex's MEMS foundry work model for providing customized solutions based on MEMS in a cost effective and well controlled manner. Factors for success are the capabilities to reformulate a customer product concept to manufacturing processes in the wafer fab, using standard process modules and production equipment. A well-controlled system increases the likelihood of a first batch success and enables fast ramp-up into volume production. The following success factors can be listed: Strong enduring relationships with the customers Highly qualified well-experienced specialists working close with the customer Process solutions and building blocks ready to use out of a library Addressing manufacturing issues in the early design phase In-house know how to meet demands for volume manufacturing. Access to a wafer fab with high capacity, good organization, high availability of equipment, and short lead times Process development done in the manufacturing environment using production equipment for easy ramp-up to volume production The article covers a method of working to address these factors: To have a long and enduring relationships with customers utilizing MEMS expertise and working close with customers, to translate their product ideas to MEMS components. To have stable process solutions for features such as Low ohmic vias, Spiked electrodes, Cantilevers, Silicon optical mirrors, Micro needles, etc, which can be used and modified for the customer needs. To use a structured development and design methodology in order to handle hundreds of process modules, and setting up standard run sheets. It is also very important to do real time process development in the manufacturing line. It minimizes the lead-time for the ramp-up of production. To have access to a state of the art Wafer Fab which is well organized, controlled and flexible, with high capacity and short lead-time for prototypes. It is crucial to have intimate control of processes, equipment, organization, production flow control and WIP. This has been addressed by using a fully computerized control and reporting system.