A new approach to generating non-permutation schedules for flowshops with missing operations

Download
2006
Tabalu, Metin
In this study, non-permutation flowshops with missing operations are considered. The primary performance criterion is the total cycle time (i.e. makespan) and the secondary criterion is the total flowtime. In order to obtain the schedule with minimum makespan and minimum total flowtime, non-permutation schedules are being generated instead of permutation ones by permitting multiple jobs bypassing stages where misisng operations occur. A heuristic algorithm has been developed in order to generate non-permutations sequences through those stages. The heuristic algorithm has been compared with the existing heuristic methods in the literature, the ones generating permutation vs. the ones generating non-permutation schedules. Computational analysis is conducted to investigate the effects of certain parameter values such as the number of machines, the number of jobs and the percentage of missing operations. The results demonstrate slight improvement in the makespan as well as a significant improvement in total flowtime of schedules generated by the new heuristic procedure compared to leading non-permutation and permutation schedule generating heuristics, where the percentage of improvement gets higher with larger percentage of missing operations.

Suggestions

Batch scheduling duling of incompatible jobs on a single reactor with dynamic arrivals
Korkmaz, Gediz; Kayalıgil, Sinan; Department of Industrial Engineering (2004)
In this study, a single machine batch-scheduling problem with incompatible jobs and dynamic arrivals is examined. The objective function is the minimization of the total flow time of the jobs. For solving problems a case specific branch and bound algorithm with a heuristic upper bound scheme and two alternative lower bound procedures is used. An extensive computational experiment is conducted to investigate the effects of certain parameters on the computation time. For the most difficult parameter combinati...
A linear programming approach to quaity improvement project and product mix selection under inspection error and rework
Şarbak, Nedret; Köksal, Gülser; Department of Industrial Engineering (2006)
In this study, the effect of inspection error on the product mix and quality projects selection in a manufacturing environment where rework and inspection errors exist is examined. It is assumed that the products (items) for which rework is necessary are reprocessed at a separate work center and 100% inspection is performed for the products both after rework and processing operations. Markov chain approach is used to compute yield and rework rates. In addition, nominal-the-best type of a quality loss functi...
Analysis of an inventory system with advance emand information and supply uncertainty
Arıkan, Emel; Süral, Haldun; Department of Industrial Engineering (2005)
In this study we address a periodic review capacitated inventory system with supply uncertainty where advance demand information is available. A stochastic dynamic programming formulation is applied with the objective of minimizing the expected inventory related costs over a finite horizon. Three different supply processes are assumed. Under the all-or-nothing type supply process and partially available supply process, the structure of optimal policy is proved to be a base stock policy and numerical example...
A Lagrangean relaxation based approach for the capacity allocation problem in flexible manufacturing systems
ÖZPEYNİRCİ, SELİN; Azizoğlu, Meral (Informa UK Limited, 2010-05-01)
This study considers the operation assignment and capacity allocation problem in flexible manufacturing systems. A set of operations is selected to be processed and assigned to the machines together with their required tools. The purchase or usage of the required tools incurs a cost. The machines have scarce time and tool magazine capacities. The objective is to maximize the total weight of the assigned operations minus the total tooling costs. We use Lagrangean relaxation approach to obtain upper and lower...
A model to evaluate inventory costs in a remanufacturing environment
Bayındır, Zeynep Pelin; Gullu, R (Elsevier BV, 2003-01-11)
In this study we investigate possible benefits of remanufacturing in inventory-related costs. In order to examine the conditions on different system parameters that make the remanufacturing option cost attractive, the return ratio is considered as a decision variable. The production environment, where the manufacturing and remanufacturing require both common and separate operations, together with the supplier's operations for the new parts and useful lifetime of the product is modeled as a queuing network. ...
Citation Formats
M. Tabalu, “A new approach to generating non-permutation schedules for flowshops with missing operations,” M.S. - Master of Science, Middle East Technical University, 2006.