An application-level technique is described for farmer-worker parallel applications which allows a worker to be added or removed from the computing farm at any moment of the run time without a ecting the overall outcome of the computation. The technique is based on uncoupling the farmer from the workers by means of a separate module which asynchronously feeds these latter with new \units of work" on an ondemand basis, and on a special feeding strategy based on bookkeeping the status of each work-unit. An augmentation of the LINDA model is nally proposed to exploit the bookkeeping algorithm for tuple management. B. Hertzberger, P. Sloot (Eds.): Proc. Int. Conf. and Exhib. on High-Performance Computing and Networking (HPCN Europe 1997) Lecture Notes in Computer Science 1225 (Springer, Berlin, 1997): 644{653