0000000000172190
AUTHOR
Adhe Kania
DESMILS : a decision support approach for multi-item lot sizing using interactive multiobjective optimization
AbstractWe propose a decision support approach, called DESMILS, to solve multi-item lot sizing problems with a large number of items by using single-item multiobjective lot sizing models. This approach for making lot sizing decisions considers multiple conflicting objective functions and incorporates a decision maker’s preferences to find the most preferred Pareto optimal solutions. DESMILS applies clustering, and items in one cluster are treated utilizing preferences that the decision maker has provided for a representative item of the cluster. Thus, the decision maker provides preferences to solve the single-item lot sizing problem for few items only and not for every item. The lot sizes …
Integration of lot sizing and safety strategy placement using interactive multiobjective optimization
We address challenges of unpredicted demand and propose a multiobjective optimization model to integrate a lot sizing problem with safety strategy placement and optimize conflicting objectives simultaneously. The novel model is devoted to a single-item multi-period problem in periodic review policy. As a safety strategy, we use the traditional safety stock concept and a novel concept of safety order time, which uses a time period to determine the additional stock to handle demand uncertainty. The proposed model has four objective functions: purchasing and ordering cost, holding cost, cycle service level and inventory turnover. We bridge the gap between theory and a real industrial problem a…
Interactive Multiobjective Optimization in Lot Sizing with Safety Stock and Safety Lead Time
In this paper, we integrate a lot sizing problem with the problem of determining optimal values of safety stock and safety lead time. We propose a probability of product availability formula to assess the quality of safety lead time and a multiobjective optimization model as an integrated lot sizing problem. In the proposed model, we optimize six objectives simultaneously: minimizing purchasing cost, ordering cost, holding cost and, at the same time, maximizing cycle service level, probability of product availability and inventory turnover. To present the applicability of the proposed model, we consider a real case study with data from a manufacturing company and apply the interactive NAUTI…
Interactive Multiobjective Optimization in Lot Sizing with Safety Stock and Safety Lead Time
In this paper, we integrate a lot sizing problem with the problem of determining optimal values of safety stock and safety lead time. We propose a probability of product availability formula to assess the quality of safety lead time and a multiobjective optimization model as an integrated lot sizing problem. In the proposed model, we optimize six objectives simultaneously: minimizing purchasing cost, ordering cost, holding cost and, at the same time, maximizing cycle service level, probability of product availability and inventory turnover. To present the applicability of the proposed model, we consider a real case study with data from a manufacturing company and apply the interactive NAUTI…
Addressing challenges of real-world lot sizing problems with interactive multiobjective optimization
Monissa tosielämän ongelmissa on useita optimoitavia tavoitefunktioita, jotka ovat ristiriidassa keskenään. Esimerkiksi tuotantoyritysten varaston ohjauksessa on toimituseriä mitoitettaessa minimoitava kustannuksia ja samalla varmistettava nimikkeiden riittävyys sekä tarpeiden mukainen varastotaso. Monitavoiteoptimointiongelmilla on monia ns. Pareto-optimaalisia ratkaisuja, jotka kuvastavat tavoitefunktioiden välisiä vaihtosuhteita. Tarvitaan päätöksentekijä valitsemaan yksi niistä käytäntöön vietäväksi päätökseksi, joka parhaiten kuvasta hänen mieltymyksiään. Iteratiivisesti mieltymykset huomioon ottavat interaktiiviset menetelmät tukevat päätöksentekijää tehokkaasti. Siksi tässä väitöskir…