Design and control issues in hybrid reconfigurable manufacturing systems.

摘要

In this dissertation we study the concept of “H&barbelow;ybrid R&barbelow;econfigurable M&barbelow;anufacturing S&barbelow;ystems” or HRMS. The basic idea involves machines that can be easily moved from a Process layout to a Product layout (or vice-versa) thus allowing the configuration of the manufacturing system for individual product orders.; A key question with respect to HRMS lies in the operational area. To date little or no work has been done which investigates the logistics of HRMS and the gains or losses in performance efficiency one can expect from such a system. The main contribution of this dissertation is the development of a method to decide how cells should be formed, when they should be formed, and how product should flow through the system.; For the situations analyzed, the observed performance in comparison with a traditional functional layout offers significant improvement in terms of flow times of the jobs, and does not penalize the utilization of resources, as traditional fixed cells do. For the first time, a study of incremental reconfigurable cell formation was performed. We found that adding a single reconfigurable cell can significantly improve the overall flow time performance of a traditional process oriented manufacturing system. A “diminishing returns” phenomenon was observed when adding further cell bays to the HRMS. The behavior of HRMS as a function of important factors for its operation was studied and compared with our expectations. We point to the scenarios where major gains can be obtained by using this new production arrangement.