Author       Custodio, L.M.M.; Sentieiro, J.J.S.; BISPO, C.F.G.; 
             Inst. de Sistemas e Robotica, Inst. Superior Tecnico, Lisbon, 
             Portugal
Title        Production planning and scheduling using a fuzzy decision system
Source       IEEE Transactions on Robotics and Automation; 
             IEEE Trans. Robot. Autom. (USA); vol.10, no.2; April 1994; pp. 
             160-8
Abstract     In this paper short-range planning and scheduling problems are 
             addressed using a nonclassical approach supported by fuzzy 
             theory. The proposed methodology uses a hierarchical structure 
             which includes three decision levels (higher, middle, lower), 
             each responsible for a different production problem with a 
             different time scale. The methodology approaches the tasks 
             associated with each level using a heuristic formulation and 
             solves the short-range planning and scheduling problems with a 
             nonstationary policy. The higher decision level determines 
             safety stock levels used to compensate for future resource 
             failures. At the middle level, loading rates are computed. This 
             is accomplished through a fuzzy controller that tends to 
             minimize the error between the cumulative production and the 
             cumulative demand while keeping the work in process below 
             acceptable values. Finally, the lower level controls the flow 
             of parts among the resources, using a modified version of the 
             Yager's fuzzy decision method. This method has the ability to 
             use several criteria to generate a decision. Simulation results 
             reveal that the proposed system exhibits good performance, in 
             terms of a high production percentage and a low WIP, under 
             resource failures and demand variations
Thesaurus    decision theory;  fuzzy set theory;  hierarchical systems;  
             production control
Other Terms  production planning;  production scheduling;  fuzzy decision 
             system;  short-range problems;  hierarchical structure;  
             heuristic formulation;  nonstationary policy;  safety stock 
             levels;  loading rates;  resource failures compensation;  work-
             in-process
ClassCodes   C1290F;  C1160;  C1140E;  C1340B
Article Type Theoretical / Mathematical
Coden        IRAUEZ
Language     English
RecordType   Journal
ControlNo.   4685409
AbstractNos. C9407-1290F-058
ISSN         1042296X
References   18
U.S. Copyright Clearance Center Code
             1042-296X/94/$04.00
Country Pub. USA
date         1226