Browsing by Author "Erkip, Nesim"

Now showing 1 - 3 of 3

Embargo
Integrating efforts for product development and market penetration
(Elsevier BV, 2023-07-16) Demirci, Ece Zeliha; Erkip, Nesim
In this paper, we build a decision model to explore an innovative firm’s budget allocation problem, which needs to be solved for each successive generation of a product. The firm introduces the product to the market through a distributor while aiming to maximize the market potential. This goal can be achieved by investing in R&D and increasing availability using subsidies registered to the distributor. We analyze the problem using a game theoretical model and provide a guideline for the funding strategy. We show that the optimal budget allocation decision is characterized by two budget thresholds and a threshold on the cost efficiency of R&D. We identify and analyze the effects of two significant parameters, total available budget and efficiency level of R&D, on the optimal solution. In addition, we assess the model’s applicability by examining the expected excess budget requirement and the distributor’s expected profit. We provide valuable managerial insights on when and how to prioritize the two components of the budget.
Embargo
Risk pooling under demand and price uncertainty
(Elsevier BV, 2023-11-22) Güllü, Refik; Erkip, Nesim
This paper studies purchasing a commodity or a perishable item under stochastically evolving and correlated prices for a distribution system environment. We consider the central purchasing of the commodity under the demand process correlated with the random price and decide on the timing and quantity of allocation to demand locations. As an implementation of the physical pooling concept, we investigate the benefits of pooling price and demand risk when the forward purchase is realized for all demand locations. We also study the benefits of informational pooling concepts by deciding on the allocation timing. Even when the demand locations are independent entities, organizing joint purchasing of a commodity may take advantage of economies of scale with a more reliable and less expensive delivery option. We develop a model to guide the purchasing and allocation of quantities and employ multi-echelon inventory theory methods and stochastic processes commonly used in financial engineering and operations management literature.
Open Access
The venue management problem: setting staffing levels, shifts and shift schedules at concession stands
(Springer, 2019) Ahipaşaoğlu, Ö.; Erkip, Nesim; Karasan, Oya Ekin
The aim of this research is to determine staffing requirements as well as shift scheduling, with the objective of maximizing the expected contribution from the venue. We specifically consider theaters where demand at concession stands is non-stationary, being largely dominated by the showtimes, the days of the week and the movie types. Determination of the number of workers and their shift in such facilities can be considered as a venue management problem. As one of the distinctive characteristics of our study, we maximize the expected contribution of venue operations while combining shift scheduling in a mathematical model. In addition to the objective function, shift scheduling differs from that in the standard literature, as shift beginning and end times are not restricted. Because of the highly variable demand in the venue management problem considered, flexible shifts are used, with flexible beginning and end times, as long as workers meet the specifications of the type to which they belong. We prove that the venue management problem under consideration is NP-complete. Under mild conditions, we show that the binary requirements of some of the variables in the model can be relaxed. Computational results of a case study are provided.