An EDF Hierarchical Scheduling Model for Bandwidth Servers

2006 ◽  
Author(s):  
J.L. Lorente ◽  
J.C. Palencia
Keyword(s):  
Hierarchical Scheduling ◽  
Scheduling Model

A Hierarchical Scheme for Open System Environments Review

2014 ◽  
Vol 950 ◽  
pp. 181-184
Author(s):  
Feng Xiang Zhang
Keyword(s):  
Embedded System ◽  
Open System ◽  
Schedulability Analysis ◽  
Earliest Deadline First ◽  
Global Level ◽  
Hierarchical Scheduling ◽  
Scheduling Model ◽  
Ready Queue ◽  
Earliest Deadline ◽  
Hierarchical Scheme

This paper focus on hierarchical scheduling for real-time applications for open embedded system environments constructed by the total bandwidth server, according to its algorithms, when a job at the head of the server's ready queue completes, the server budget is replenished immediately if the ready queue is not empty. This paper gives some examples to the solutions proposed by Deng et al for a two-level hierarchical scheduling model in which the global level of the system is earliest deadline first, and the local scheduler could be any algorithm. The scheduling algorithms and schedulability analysis for the tasks are reviewed in an open system where the applications could be modeled as executing on a slow processor.

scholarly journals Operating Rooms efficiency: leveraging data to improve management of elective surgery

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Quercioli ◽  
G A Carta ◽  
G Cevenini ◽  
G Messina ◽  
N Nante ◽  
...  
Keyword(s):  
Historical Data ◽  
Elective Surgery ◽  
District General Hospital ◽  
Operating Rooms ◽  
Accurate Estimation ◽  
Surgical Time ◽  
Accurate Analysis ◽  
Management Efficiency ◽  
Scheduling Model ◽  
The Mean

Abstract Background Careful scheduling of elective surgery Operating Rooms (ORs) is crucial for their efficient use, to avoid low/over utilization and staff overtime. Accurate estimation of procedures duration is essential to improve ORs scheduling. Therefore analysis of historical data about surgical times is fundamental to ORs management. We analyzed the effect, in a real setting, of an ORs scheduling model based on estimated optimum surgical time in improving ORs efficiency and decreasing the risk of overtime. Methods We studied all the 2014-2019 elective surgery sessions (3,758 sessions, 12,449 interventions) of a district general hospital in Siena's Province, Italy. The hospital had3 ORs open 5 days/week 08:00-14:00. Surgery specialties were general surgery, orthopedics, gynecology and urology. Based on a pilot study conducted in 2016, which estimated a 5 times greater risk of having an OR overtime for sessions with a surgical time (incision-suture)>200 minutes, from 2017 all the ORs were scheduled using a maximum surgical time of 200 minutes calculated summing the mean surgical times for intervention and surgeon (obtained from 2014-2016 data). We carried out multivariate logistic regression to calculate the probability of ORs overtime (of 15 and 30 minutes) for the periods 2014-2016 and 2017-2019adjusting for raw ORs utilization. Results The 2017-2019 risk of an OR overtime of 15 minutes decreased by 25% compared to the 2014-2016 period (OR = 0.75, 95%CI=0.618-0.902, p = 0.003); the risk of a OR overtime of 30 minutes decreased by 33% (OR = 0.67, 95%CI= 0.543-0.831, p < 0.001). Mean raw OR utilization increase from 62% to 66% (p < 0.001). Mean number of interventions per surgery sessions increased from 3.1 to 3.5 (p < 0.001). Conclusions This study has shown that an analysis of historical data and an estimate of the optimal surgical time per surgical session could be helpful to avoid both a low and excessive use of the ORs and therefore to increase the efficiency of the ORs. Key messages An accurate analysis of surgical procedures duration is crucial to optimize operating room utilization. A data-based approach can improve OR management efficiency without extra resources.

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