Optimering av placering och antal ytor för tomma rullcontainrar på lager
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
The Master Thesis has been performed at ICA Sverige AB’s warehouse unit in Västerås. The unit is a central warehouse unit, distribution unit and distribution point. It delivers among others pantry and non-food products.
The main part of ICA’s goods is distributed in mobile cages called RC (Rolling Cage) which result in a daily demand of approximately 7000 RC. Hence, the flow of RC to and within the warehouse is an important part of ICA’s operations. For each picking order a warehouse employee collects four empty RCs from a RC area. Today there are two RC areas. Both placed close to the loading areas for outgoing goods. RC areas are used for storing of empty RC.
The purpose of the Master Thesis is to evaluate the most optimal solution of combinations (quantity and location) of RC areas based on minimizing distances and costs. According to the optimization process the problem was charted and simplified. By formulating an optimization model the warehouse employees’ anticipated driving distances are calculated based on given assumptions of combinations of RC areas. The optimization model provides the information needed in order to compare the driving distances and the incurred related costs for different combinations of RC areas. The optimization model was implemented in the programming language Python.
The optimization model has been tested for combinations of two, three, four and dynamic RC areas. The conclusions that have been made are based upon minimizing the driving distances, lessen the congestions and to pursue the usage of appropriate areas. The result shows that today’s placement of RC areas is a good solution for a combination of two RC areas. The most beneficial combination of three RC areas gives cost savings of approximately 750 000 SEK/year. A combination of four RC areas results in cost increase and is therefore not preferred. Dynamic RC areas gives cost savings of approximately 112 000 SEK/year for the optimal combination of two fixed RC areas and one dynamic area, and approximately 210 000 SEK/year for a combination of two fixed areas and two dynamic RC areas. Dynamic RC areas require thorough planning.
Based on the result, ICA is recommended to evaluate implementing three RC areas in the warehouse unit. To enable three RC areas ICA need to evaluate the overall layout of the warehouse areas and available space.
A tool for planning the internal deliveries of empty RC has been created from the result of the optimization model. The tool has the purpose to level the flow of RC to the warehouse unit which could ultimately lead to reduced transports and buffer areas as well as to better control and demand on external deliveries. The tool has been implemented in Microsoft Excel.
Title: Optimization of the Store Location and Numbers of Areas for Empty Rolling Cages
Place, publisher, year, edition, pages
2015. , 52 p.
IdentifiersURN: urn:nbn:se:umu:diva-106707OAI: oai:DiVA.org:umu-106707DiVA: diva2:844117
ICA Sverige AB
Master of Science in Engineering and Management
Persson, Leif, Universitetslektor
Lundow, Per-Håkan, Universitetslektor