Order driven flexible shop management

Download
2011
Bulut, Aykut
The difficulties in responding to variation in product order mixes and load levels effectively in make to order are known. Most of the existing approaches consider releasing jobs to the shop (input control), changing capacity levels (output control) in a controlled way, order acceptance with different definitions of work load and due date assignment. Controlling the processes, routing options and the order accepting capacity with various tool combinations that will decrease tool loading are not considered properly. However the manufacturing flexibility provided by the computer numerically controlled (CNC) machines, provides both part variety and due date achievement given a reasonable extra capacity. Positive effects of flexibility on the due date achievement of the make to order is shown with a variety of experimental and field studies leaving little doubt. However taking flexibility only as a strategic issue and not considering it as a means of planning and management in either the short term or medium term decisions have been commonplace practice. In this study, benefits of providing three kinds of flexibility, considering order pool and acceptance probability of the new arrivals in a periodic setting, is the focal issue. If the required flexible environment is provided, the necessity to make a detailed job loading, route planning and scheduling will be reduced to a low level and a high shop congestion and due date achievement will be realized simultaneously. A typical realistic shop with a scaled part mix is assumed in the flexibility management modeling and simulation experiments are conducted applying periodical flexibility planning approach. These experiments briefly support the ideas that worth of anticipation is more than plain expectations and flexibility improves robustness.

Suggestions

Solution approaches for flexible job shop scheduling problems
Balcı, Şerife Aytuğ; Azizoğlu, Meral; Oğuzsoy, Cemal Berk; Department of Industrial Engineering (2013)
In this thesis, we consider a flexible job shop scheduling problem existing in discrete parts manufacturing industries. We are motivated by the production environment of Roketsan Missiles Industries Incorporation, operating at Turkish defense industry. Our objective is to minimize the total weighted completion times of the jobs in the system. We formulate the problem as a mixed integer linear program and find that our model could find optimal solutions only to small sized problem instances. For medium and l...
A new concept on sampling systems by air cannon application
Yünel, Ufuk; Hiçyılmaz, Cahit; Department of Mining Engineering (2004)
The most important criterion in industrial production processes is to control the required product quality and comply with the standards pre-described for the application during any stage of the process. This control begins from the entry of raw material to the plant and continues with pre-determined points. Mainly two different types of inspection and analyses are used to examine the material quality and content. These are physical and chemical analysis.In most of the production plants above mentioned anal...
A Remanufacturing system with imperfect sorting: deterministic and probabilistic models
Tan, Merve; Bakal, İsmail Serdar; Yüksel Özkaya, Banu; Department of Industrial Engineering (2018)
In this study, we focus on inaccurate sorting process with classification errors in a reverse supply chain comprising a remanufacturer and a collector under deterministic demand in a single time period. The collector acquires used items from end-users and the remanufacturer reproduces them to serve the deterministic demand of remanufactured products. There are two sources of uncertainty: uncertain quality of used items and uncertain quality of sorted items due to imperfect testing. Used items are categorize...
Production and stock management under manufacturer and customer driven substitution
Töre, Nurşen; Savaşaneril Tüfekci, Seçil; Department of Industrial Engineering (2014)
In this thesis, the stock management problem of a manufacturer is studied in the presence of product substitution flexibility. The study consists of two parts. In the first part, the manufacturer's joint production scheduling and product substitution decisions are analyzed. It is assumed that there are multiple substitutable items and for each item, and inventory is kept separately. If upon demand arrival, stock is not available, then demand is backordered. Depending on the inventory level, it is possible t...
Convex envelope results and strong formulations for a class of mixed-integer programs
Denizel, M; Erenguc, SS; Sherali, HD (1996-06-01)
In this article we present a novel technique for deriving the convex envelope of certain nonconvex fixed-charge functions of the type that arise in several related applications that have been considered in the literature. One common attribute of these problems is that they involve choosing levels for the undertaking of several activities. Two or more activities share a common resource, and a fixed charge is incurred when any of these activities is undertaken at a positive level. We consider nonconvex progra...
Citation Formats
A. Bulut, “Order driven flexible shop management,” M.S. - Master of Science, Middle East Technical University, 2011.