An Inventory Model with Two Classes of Customers in On-line Rental Service: Consumer Model Approach

This short version of the paper offers a model and analysis of the rental process at a subscription-based business like Netflix. We analyze a priority scheduling scheme, currently in use, that gives priority to light renters over heavy renters and show that, in some situations, it may be more profitable for the firm to give priority to heavy renters which is opposite to the Netflix’s current practice. The conditions determining the optimal initial inventory are proved analytically. Extensions are briefly discussed

REDUCING CUSTOMER WAIT TIME AND IMPROVING PROCESSES AT ABC’s ATV RENTALS

This project serves to explore the system bottlenecks of a small, family owned ATV rental company. The main objective is to reduce the average time a customer spends in the system, focusing on customer wait time as well as other areas that can be improved. This was done by collecting time studies and inputting the values into simulation software, which was run to represent the current system as well as various other possible scenarios encountered by rental companies. While creating the simulation, adaptive techniques were incorporated into the simulation. These techniques aim to increase the durability and reusability of the simulation for future use. An example of incorporating adaptive simulation is through having the simulation software draw values from an Excel spreadsheet. This example of adaptive simulation targets the efficiency of use, as values and formulas are easier to calculate and visualize in Excel than the simulation software. Through the scenarios created in the simulation software, the main system bottleneck was discovered to be the company’s trailer fleet size. Several scenarios were then created to further explore the theory and resulted in confirming it. The results of this analysis conclude that to reduce customer wait time in the system, the company should increase its fleet size by one trailer. A secondary, no cost solution is to eliminate ATV load/unload times by moving ATVs to the dunes prior to customer arrival instead of loading them on a customer by customer basis

Capacity flexibility of a maintenance service provider in specialized and commoditized system environments

In the last decades, after-sales services have become increasingly important since service is a source of differentiation as well as a lucrative business opportunity due to the substantial amount of revenue that can be generated from the products in use throughout their life cycle. Following this trend, many after-sales service providers have emerged in the market or evolved as semi-autonomous units within the OEM (Original Equipment Manufacturer) companies. In this thesis, we focus on the maintenance aspect of after-sales services. We assume that a maintenance service provider (MSP) is running a repair shop in an environment with numerous operating systems that are prone to failure. The MSP is responsible for keeping all systems in an environment up and working. We mainly focus on two types of environments: 1) Specialized System Environment 2) Commoditized System Environment. The systems in the first environment are highly customized. They are designed and built specifically following the owners’ precise requirements. Defense systems, specific lithography systems, mission aircrafts or other advanced/complex, engineer-to-order capital goods are examples of such specialized systems. Due to the diversity of owners’ requirements, each system develops many unique characteristics, which make it hard, if not impossible, to find a substitute for the system, in the market as a whole. In the second environment, the systems are more generic in terms of their functionality. Trucks, cranes, printers, copy machines, forklifts, computer systems, cooling towers, some common medical devices (i.e. anesthesia, x-ray and ultrasound machines, etc…), power systems are examples of such more commoditized systems. Due to the more generic features of the owners’ requirements, it is easier to find a substitute for a system in the market, with more or less the same functionality, for short-term hiring purposes. Upon a system breakdown, the defective unit (system/subsystem) is sent to the repair shop. MSP is responsible for the repair and also liable for the costs related to the down time. In order to alleviate the down-time costs, there are chiefly two different downtime service strategies that the MSP can follow, depending on the environment the repair shop is operating in. In the specialized system environment, the MSP holds a spare unit inventory for the critical subsystem that causes most of the failures. The downtime service related decision in such a case would be the inventory level of the critical spare subsystems. On the other hand, in the commoditized system environment, rather than keeping a spare unit inventory, the MSP hires a substitute system from an agreed rental store/3rd party supplier. The downtime service related decision in this case is the hiring duration. Next to the above downtime service related decisions, repair shop’s capacity level is the other primary determinant of the systems’ uptime/availability. Since maintenance is a labor-intensive industry, the capacity costs constitute a large portion of the total costs. Increasing pressure on profitability and the growing role of External Labor Supplier Agencies motivate service provider firms to scrutinize the prospects and possibilities of capacity flexibility by using contingent workforce. For various reasons, flexible capacity practices in real life are often periodic, and the period length is both a decision parameter and a metric for flexibility. A shorter period length implies more frequent adapting possibilities and a better tailoring of the capacity. On the other hand, the flexible capacity cost per unit time is higher for shorter period lengths due to the compensating wage differentials, which models the relation between the wage rate and the unpleasantness, risk or other undesirable attributes of the job. Certainly, short period length in this context is an undesirable attribute for the flexible capacity resource, as it mandates the resource to switch tasks and to be ready/available more frequently, without the guarantee that s/he will be actually employed. Therefore, we propose several empirically testable functional forms for the cost rate of a flexible capacity unit, which are decreasing with the period length and, in the limit, approaches to the cost rate of a permanent capacity unit from above. In the light of discussions above, we investigate three different capacity modes in this dissertation: ¿ Fixed Capacity Mode: In this mode, all of the capacity is permanent and ready for use in the repair shop. This mode serves as a reference point in order to assess the benefits of other flexible capacity modes. The relevant capacity decision in this mode is the single capacity level of the repair shop. ¿ Periodic Two-Level Capacity Mode: In this mode, we assume two levels of repair shop capacity: permanent and permanent plus contingent capacity levels. The permanent capacity is always available in the system, whereas the deployment of the contingent capacity is decided at the start of each period based on the number of units waiting to be repaired in the shop. The relevant capacity decisions in this mode are the permanent and contingent capacity levels, the period length and the states (in terms of number of defective units waiting) where the contingent capacity is deployed. ¿ Periodic Capacity Sell-Back Mode: In this mode, the failed units are sent to the repair shop at regular intervals in time. Due to this admission structure, when the repair of all the defective units in the repair shop are completed in a period, it is known that no new defective parts will arrive to the shop at least until the start of the next period. This certainty in idle times allows for a contract, where the repair shop capacity is sold at a reduced price to the capacity agency where it is assigned to other tasks until the start of the next period. The original cost of the multi-skilled repair shop capacity per time unit is higher than the permanent capacity cost that is mentioned in previous modes due to the compensation factors such as additional skills, frequent task switching and transportation/transaction costs. Similar to the previous capacity mode, the compensation decreases with the length of the period length. The relevant capacity decisions in this mode are the capacity level and the period length. The primary goal of this thesis is to develop quantitative models and methods for taking optimal capacity decisions for the repair shop in the presence of the capacity modes described above and to integrate these decisions with the other downtime service decisions of the MSP for two different types of system environments (specialized vs. commoditized). After the introduction of the problem, concepts and literature review are given in Chapters 1. In Chapter 2, we focus on the use of capacity flexibility in the repair operations of the MSP in specialized system environment. The capacity related decisions are integrated with the decision on the stock level of the spare unit inventory for all three capacity modes. In Chapter 3 we investigate the same three capacity modes in a (partially) commoditized system environment, where hiring a substitute system for a pre-determined, uniform duration becomes the conventional method upon a failure. In this chapter the decision on the hiring duration is integrated with the other capacity related decisions. Then we provide some preliminary analysis and give the early results on the hybrid strategy where both "keeping stock" and "hire substitute" strategies are followed. Finally in Chapter 4, we summarize our results, give the conclusion and discuss the topics covered in this thesis with a brief exploration on the future research. The numerical results reveal that, in both specialized and commoditized system environments, substantial cost savings (up to 70%) can be achieved under periodic two-level capacity and periodic capacity sell-back modes compared to the fixed capacity mode. However, both period length and the compensation scheme of the capacity resources greatly influence the savings, even in some cost instances, flexible modes (periodic two-level and capacity sell-back) become less economical compared to the fixed capacity mode. Cost parameter instances in which each of the 3 capacity modes becomes cost-optimal, the characteristics of the cost savings and the sensitivity analysis of cost/policy parameters are investigated in both of the system environments in Chapter 2 and Chapter 3, respectively. In the commoditized system environment, under the same cost parameter settings, the hiring substitute from an external supplier for a fixed duration causes a better, more refined and certain control compared to keeping an inventory. Hybrid strategy, in which a substitute is hired after a stock-out instance, is applicable in commoditized as well as commoditizing (previously specialized systems that are in the ongoing commoditization process) system environments. Hybrid strategy outperforms both "only keeping stock" and "only hiring substitute" alternatives; however, in the commoditized system environment, a MSP may still have a proclivity to employ the "hiring substitute" strategy only, because it does not require any initial investment, which is convenient for SMEs. These issues will be explicated further in Chapter 5. We believe that the framework, the design and analysis of the problems addressed as well as the results and the insights obtained in this dissertation can help and motivate other researchers/practitioners to further investigate the cost saving prospects from capacity flexibility in maintenance service operations. We also anticipate that the commoditization framework described in this thesis will be increasingly useful in the future, since the commoditization of the parts/machines will be much more widespread, pushing all the after-sales service providers to compete on the efficiency of their operatio

Araç kiralama sektöründe rekabet belirleyicilerinin işletme performansına etkisi : turizm destinasyonlarında bir araştırma

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Turizm sektörünün ulaştırma alt sistemlerinden karayolu ulaşımı içinde yer alan araç kiralama işletmeleri turistlere bir destinasyona ulaşmada hız, esneklik, konfor ve bireysellik sunmaktadır. Araç kiralama işletmeleri, XX. yüzyılda otomobilin seri üretime başlamasıyla ortaya çıkmıştır. Günümüzde önemli bir sektör haline gelen araç kiralama diğer sektörler gibi artan küresel rekabetten ve hızlı değişimden etkilenmektedir. Böyle bir değişme ve gelişme sonucunda her sektörde işletme başarısına etki eden bazı rekabet unsurları öne plana çıkmaktadır. Bu doğrultuda çalışmanın amacı, araç kiralama sektöründe rekabet belirleyicilerinin işletme performansı üzerine etkisini tespit etmektir. Araştırma toplam dört bölümden oluşmaktadır. Birinci bölümde turizm sektörü ve turizm ulaştırmasına yer verilmiştir. İkinci bölümünde araç kiralama sektörünün yapısı incelenmiştir. Üçüncü bölümde rekabet araç kiralama işletmeleri bağlamında ele alınmıştır. Dördüncü bölümde ise araştırma bulgularına yer verilmiştir. Çalışma hem nitel hem de nicel araştırma yöntemine dayanmaktadır. Araştırmada önce İstanbul ve Antalya'daki 24 araç kiralama işletmesi yöneticisi ile görüşme yapılmıştır. Daha sonra İstanbul, Ankara, İzmir ve Antalya'daki toplam 230 araç kiralama işletmesinden anket yoluyla veriler elde edilmiştir. Araştırma sonucunda araç kiralama sektöründe bilgi teknolojileri kullanımı, stratejik işbirlikleri, hizmet kalitesi, birleşme veya satın alma, pazarlama iletişimi ve rekabetçi fiyat sunma rekabet belirleyicileri olarak saptanan ana unsurlardır. Rekabet belirleyicilerinden bilgi teknolojileri kullanımı, hizmet kalitesi ve pazarlama iletişiminin işletme performansını etkilediği tespit edilmiştir. Öte yandan farklılık analizleri sonucunda, işletmelerin faaliyet gösterdiği il, çalışan sayısı, araç sayısı, şube sayısı ile bilgi teknolojileri kullanımı, pazarlama iletişimi, işletme performansı, rekabet yoğunluğu ve hizmet kalitesi faktör ortalamaları arasında istatistiksel açıdan anlamlı bir farklılık bulunmuştur. Çalışmanın temel kısıtı, araştırmanın İstanbul, Ankara, Antalya ve İzmir illerinde faaliyet gösteren araç kiralama işletmelerinde yapılmış olmasıdır. İleride bu çalışmaya benzer yapılacak çalışmalara öneri olarak Türkiye genelini kapsayan araştırmalar yapılabilir. Ayrıca ortaya çıkan sonuçlar bu araştırma ile karşılaştırılabilir. Anahtar Kelimeler : Araç Kiralama ĠĢletmeleri, Turizm, Rekabet Belirleyicileri, Turizm UlaĢtırmasıCar rental businesses within the highland transportation of the sub-systems of tourism sector, offer the tourists speed, flexibility, comfort and individualism in reaching to a destination. The car rental businesses occurred with the start of the serial production of the automobile in 20th century. Car rental which becomes an important sector in present, affects from the increasing global competition and rapid change as well as the other sectors. As the result of this change and improvement, some competition elements affecting the success of the business become prominent. The purpose of this study is to determine the effect of the competition determinants in car rental sector on the performance of the business. The research consists of four sections in total. In the first section, tourism sector and tourism transportation is studied. In the second sector, the structure of the car rental sector is evaluated. In the third section, the competition is considered in terms of car rental sector. In the fourth section, research findings are presented. The study is based on both qualitative and quantitative research method. Before the research, an interview is made with 24 car business executives in İstanbul and Antalya. Then data is collected from 230 car rental businesses in Istanbul, Ankara, İzmir and Antalya through questionnaire method. As the result of the research, usage of the information technologies, strategically cooperation, service quality, merger and purchase, marketing communication and offering competitive prices are the main elements which are determined as the competition determinants. It is determined that usage of information Technologies, service quality and marketing communication from the competition determinants, affect the performance of the business. Besides as the result of the dissimilarity analysis, a meaningful disparity is found in terms of statistical among the province of the business, number of employees, number of cars, branch number, usage of information Technologies, marketing communication, performance of the business, competition density and service quality factor averages. The main congestion of the study is; the study is made in the car rental businesses which carry out activity in Istanbul, Ankara, Antalya and İzmir. As a suggestion to the similar studies to be made in future, the research can be made which covers overall Turkey. Keywords: Car Rental Companies, Tourism, Competitive Determinants, Tourism Transpor