Scheduling Methods for Efficient Stamping Operations at an Automotive Company

We consider scheduling issues at Beyçelik, a Turkish automotive stamping company that uses presses to give shape to metal sheets in order to produce auto parts. The problem concerns the minimization of the total completion time of job orders (i.e., makespan) during a planning horizon. This problem may be classified as a combined generalized flowshop and flexible flowshop problem with special characteristics. We show that the Stamping Scheduling Problem is NP‐Hard. We develop an integer programming‐based method to build realistic and usable schedules. Our results show that the proposed method is able to find higher quality schedules (i.e., shorter makespan values) than both the company's current process and a model from the literature. However, the proposed method has a relatively long run time, which is not practical for the company in situations when a (new) schedule is needed quickly (e.g., when there is a machine breakdown or a rush order). To improve the solution time, we develop a second method that is inspired by decomposition. We show that the second method provides higher‐quality solutions—and in most cases optimal solutions—in a shorter time. We compare the performance of all three methods with the company's schedules. The second method finds a solution in minutes compared to Beyçelik's current process, which takes 28 hours. Further, the makespan values of the second method are about 6.1% shorter than the company's schedules. We estimate that the company can save over €187,000 annually by using the second method. We believe that the models and methods developed in this study can be used in similar companies and industries.     

The effect of urinary incontinence on sexual functioning in turkish women of reproductive and menopausal ages

Objectives: The primary objective was to investigate the effects of urinary incontinence (UI) on Turkish women's sexual functioning. Methods: We evaluated 396 women and divided them into 4 groups: reproductive-aged women without UI (Group A), reproductive-aged women with UI (Group B), menopausal-aged women without UI (Group C), and menopausal-aged women with UI (Group D). Results: The mean Female Sexual Function Index (FSFI) score was significantly higher and the Beck's Depression Inventory scores were significantly lower in Group A. FSFI scores showed a strong negative correlation with age and parity and a strong positive correlation with years of education. Conclusions: Our findings suggest that UI is an independent risk factor for female sexual problems.