Development of models for order picking area selection and design

U savremenim uslovim poslovanja skladište je bitna logistička komponenta lanaca snabdevanja. Pred njega se postavljaju sve kompleksniji zadaci, što u značajnoj meri usložnjava njegovu strukturu i funkcionisanje – pre svega procesa koji se realizuju. Od tih procesa, a naročito u slučaju skladišta distributivnog tipa (Distributivnog centra), posebno mesto imaju procesi komisioniranja. Performanse procesa komisioniranja su u velikoj meri zavisne od izabrane – primenjene tehnologije skladištenja, layout-a, tehnološkog oblika komisionog sistema, i načina na koji je sam proces organizovan i upravljan. Veoma značajan aspekt ovog problema, do sada nedovoljno istražen u literaturi, odnosi se direktno na pitanje izbora i uobličavanja komisione zone. Ovaj problem u svom integralnom obliku bio je predmet istraživanja u okviru ove disertacije. Za rešavanje problema izbora i uobličavanja komisione zone je predložena i razvijena nova iterativna procedura sa dva hijerarhijska nivoa odlučivanja. Na prvom nivou – u okviru konceptualne faze identifikuju se prihvatljive varijantne tehnološke koncepcije komisione zone. Za dolaženje do skupa prihvatljivih varijanti se predlaže i primenjuje novi metodološki pristup koji, u odnosu na standardne, omogućava brže rešavanje zadataka generisanja i izbora. Nа drugom nivou procedure, u fazi uobličavanja varijanti, pristupa se njihovom dovođenju u svoj najpovoljniji oblik. Tom prilikom se određuju bitni projektni parametri sa ciljem ostvarenja zadatih performansi skladišnog sistema, odnosno njegovog sistema za komisioniranje. Centralno mesto na ovom nivou procedure ima određivanje veličine komisione zone zbog njenog velikog uticaja na performanse i operativne troškove. Za određivanje optimalne veličine komisione zone predlaže se primena odgovarajućeg iterativnog postupka. U okviru ovog postupka za rešavanje određenih zadataka odlučivanja koriste se odgovarajući parcijalni modeli (pre svega za optimalnu alokaciju skladišnog kapaciteta na robe i za procenu specifičnih skladišnih troškova). U postupak određivanja optimalnih veličina komisione zone uključene su sve izabrane varijantne koncepcije identifikovane na prvom hijerarhijskom nivou. Procedura se završava, shodno uvedenim kriterijumima, izborom predloga rešenja koncepcije komisione zone koji se koristi u daljim fazama procesa projektovanja skladišta. Radi demonstracije predložene procedure dat je prikaz njene primene na karakterističnom zadatku projektovanja komisione zone u skladištu. Analiza ostvarenih rezultata je pokazala značajan nivo primenljivosti ove procedure i njenih parcijalnih modela na rešavanje problema u domenu izbora i uobličavanja komisione zone u procesu tehnološkog projektovanja skladišta...In a modern business environment warehouse represents an important logistic component of supply chains. Warehousing faces increasing complexity of tasks, which results in higher complexity of a warehouse's structure and its operations. That is especially notable in distribution type of the warehouses (distribution centers - DC), where order picking processes are dominant type of processes. Order picking performances mostly depend on chosen or applied warehousing technology, layout, technological design of an order picking system and the process organization and control. Selection and design of an order picking area is one important aspect of this problem which is not much covered in the literature and therefore represents main research focus of this doctoral dissertation. As the solution for the problem of the order picking areas selection and design, a new iterative procedure based on two hierarchical decision levels has been proposed and developed. Acceptable variants of a technological concept of the order picking area are identified on the first level (conceptual level). This methodological approach enables faster solving process with respect to develop and selection of order picking area than the standard one. On the second level, which is focused on a design of technological variants, order picking area variants have been adapted to achieve their most adequate form. In this level, relevant project parameters have been determined, so that goal performances of the warehousing system, i.e. its order picking system are achieved. Focus of this level is an issue of the order picking size, due to its influence to performances and operational costs. An iterative modeling/designing procedure has been proposed and applied in order to find an optimal size of the order picking area. In this procedure specific partial models have been used to find optimal allocation of warehousing capacity to (particular) stock (types), as well as to estimate specific warehousing costs. The procedure of finding the optimal size of order picking area includes all selected technological variants identified in the first hierarchical level. The procedure is ending when, according on selected criteria, the solution for order picking area is found. This solution is then used in further phases of the warehouse design project. To test proposed procedure, one characteristic task of the order picking design is solved. Analysis of results shows that the proposed procedure and partial models have significant level of applicability for problems that belong to the area of selection and design of the order picking area, within process of the technological design of the warehouse..