Robust operating room planning considering upstream and downstream units: A new two-stage heuristic algorithm

2020 ◽  
Vol 143 ◽  
pp. 106387
Author(s):  
Amirhossein Moosavi ◽  
Sadoullah Ebrahimnejad
2008 ◽  
Vol 185 (3) ◽  
pp. 1026-1037 ◽  
Author(s):  
Mehdi Lamiri ◽  
Xiaolan Xie ◽  
Alexandre Dolgui ◽  
Frédéric Grimaud

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Yu Lin ◽  
Zheyong Bian ◽  
Shujing Sun ◽  
Tianyi Xu

In recent years, logistics systems with multiple suppliers and plants in neighboring regions have been flourishing worldwide. However, high logistics costs remain a problem for such systems due to lack of information sharing and cooperation. This paper proposes an extended mathematical model that minimizes transportation and pipeline inventory costs via the many-to-many Milk-run routing mode. Because the problem is NP hard, a two-stage heuristic algorithm is developed by comprehensively considering its characteristics. More specifically, an initial satisfactory solution is generated in the first stage through a greedy heuristic algorithm to minimize the total number of vehicle service nodes and the best insertion heuristic algorithm to determine each vehicle’s route. Then, a simulated annealing algorithm (SA) with limited search scope is used to improve the initial satisfactory solution. Thirty numerical examples are employed to test the proposed algorithms. The experiment results demonstrate the effectiveness of this algorithm. Further, the superiority of the many-to-many transportation mode over other modes is demonstrated via two case studies.


2018 ◽  
Vol 121 (8) ◽  
pp. e159-e160
Author(s):  
Gül Özlem Yıldırım ◽  
Gülseren Keskin ◽  
Halil Yıldırım ◽  
Elif Aktekin ◽  
Nurcan Güzelay ◽  
...  

2017 ◽  
Vol 15 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Altair da Silva Costa Jr

ABSTRACT Objective To evaluate the indicators duration of anesthesia, operative time and time patients stay in the operating rooms of different surgical specialties at a public university hospital. Methods It was done by a descriptive cross-sectional study based on the operating room database. The following stages were measured: duration of anesthesia, procedure time and patient length of stay in the room of the various specialties. We included surgeries carried out in sequence in the same room, between 7:00 a.m. and 5 p.m., either elective or emergency. We calculated the 80th percentile of the stages, where 80% of procedures were below this value. Results The study measured 8,337 operations of 12 surgical specialties performed within one year. The overall mean duration of anesthesia of all specialties was 178.12±110.46 minutes, and the 80th percentile was 252 minutes. The mean operative time was 130.45±97.23 minutes, and the 80th percentile was 195 minutes. The mean total time of the patient in the operating room was 197.30±113.71 minutes, and the 80th percentile was 285 minutes. Thus, the variation of the overall mean compared to the 80th percentile was 41% for anesthesia, 49% for surgeries and 44% for operating room time. In average, anesthesia took up 88% of the operating room period, and surgery, 61%. Conclusion This study identified patterns in the duration of surgery stages. The mean values of the specialties can assist with operating room planning and reduce delays.


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