Browsing by Author "Jeffrey Joines, Committee Co-Chair"

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    The Effects of Information Sharing in a Two-stage Apparel Supply Chain Using Policy Characterization and Simulation
    (2007-12-18) Yoon, Seonghoo; Jeffrey Joines, Committee Co-Chair; Kristin Thoney-Barletta, Committee Chair
    The purpose of this research is to characterize the inventory policies of a two-stage apparel supply chain, consisting of an apparel producer and a retail store, based on the optimal policies obtained by a Markov Decision Process (MDP) and to test the characterized policies on seasonal demand patterns using simulation. First, the optimal policies for the apparel producer and the retail store were obtained using the MDP experiments. Based on these results, characterized policies for the apparel producer and the retail store were obtained by comparing the MDP results to standard policies such as (Q, r), (s, S), and echelon stock policies. The characterized policies were found to be either optimal or near-optimal. By using the policy characterized for the changes in cost, the total gain of the supply chain was increased compared to using the base policy for that problem. A neural network model found the characterized policies for the apparel producer and the retail store when multiple numbers of costs were changed. The neural network models also obtained near-optimal policies for the models used in this research. Then, the two-stage apparel supply chain with different types of seasonal demands was simulated. Since the apparel producer and the retail store's inventory policies were highly correlated to the mean and coefficient of variation (CV) of demand, corresponding policies were required to be changed when the demand had a seasonal pattern in order to increase the total gain of the supply chain. Different options were compared to find the optimal week to change the policy. Option B, which changed policies one week prior to the increase in the mean of demand and changed policies in the same week that the mean of demand decreases, produced the highest gains for both the no information sharing model and the information sharing model. The simulation results showed that by sharing the retail store's inventory information, both the apparel producer and the retail store could increase their gains. Moreover, the retail store's gain was increased by a higher percentage than the apparel producer.
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    Modeling the Production Planning and Scheduling Activities and Data in Warp Knitting, Dyeing and Finishing
    (2003-02-12) Areias, Joao S.; George Hodge, Committee Co-Chair; Gary Smith, Committee Member; Jeffrey Joines, Committee Co-Chair
    Production planning and scheduling plays a fundamental role inside any manufacturing organization, and is a core competence since it interacts with all the functional areas of the organization. Production planning and scheduling is the basic tile of the first information systems upon which enterprise resource planning has been built on. Nevertheless, despite the importance of this function, companies often fail to see the importance of planning and scheduling as well as study the best possible solutions for the function, one such industry is warp knitting. Using the IDEF0 and IDEF1X modeling methodologies, a model for representing the activities and the data involved in the production planning and scheduling of a warp-knitting, dyeing and finishing company has been developed. The models were validated by gathering information from visits made to companies operating in the area of the model. The models may be used as a starting point for an information management solution in production planning and scheduling in the warp knitting, dyeing and finishing industry, as well as determining all the areas that impact a scheduling solution.