scholarly journals An approach to reduce turn around timeand waiting timeby the selection of round robin and shortest job first algorithm

2018 ◽  
Vol 7 (2.8) ◽  
pp. 667 ◽  
Author(s):  
Sarvesh Kumar ◽  
Gaurav Kumar ◽  
Komal Jain ◽  
Aditi Jain

In this research,a study on operating system tells about its working,  how it helps as interface between user software and system  hardware .To implement this, different scheduling is used to provide multiple processing in a hardware. There are different levels of scheduler applied in different levels of process from ready queue to termination. This paper focuses on the average amount of waiting time and amount of turnaround time of processes. The proposed algorithm purely defines less waiting time and turnaround time as compared to the round robin scheduling and shortest job first scheduling algorithm.

Author(s):  
Sonia Zouaoui ◽  
Lotfi Boussaid ◽  
Abdellatif Mtibaa

<p>This paper introduce a new approach for scheduling algorithms which aim to improve real time operating system CPU performance. This new approach of CPU Scheduling algorithm is based on the combination of round-robin (RR) and Priority based (PB) scheduling algorithms. This solution maintains the advantage of simple round robin scheduling algorithm, which is reducing starvation and integrates the advantage of priority scheduling. The proposed algorithm implements the concept of time quantum and assigning as well priority index to the processes. Existing round robin CPU scheduling algorithm cannot be dedicated to real time operating system due to their large waiting time, large response time, large turnaround time and less throughput. This new algorithm improves all the drawbacks of round robin CPU scheduling algorithm. In addition, this paper presents analysis comparing proposed algorithm with existing round robin scheduling algorithm focusing on average waiting time and average turnaround time.</p>


2020 ◽  
Vol 10 (15) ◽  
pp. 5134
Author(s):  
Samih M. Mostafa ◽  
Hirofumi Amano

Minimizing time cost in time-shared operating system is the main aim of the researchers interested in CPU scheduling. CPU scheduling is the basic job within any operating system. Scheduling criteria (e.g., waiting time, turnaround time and number of context switches (NCS)) are used to compare CPU scheduling algorithms. Round robin (RR) is the most common preemptive scheduling policy used in time-shared operating systems. In this paper, a modified version of the RR algorithm is introduced to combine the advantageous of favor short process and low scheduling overhead of RR for the sake of minimizing average waiting time, turnaround time and NCS. The proposed work starts by clustering the processes into clusters where each cluster contains processes that are similar in attributes (e.g., CPU service period, weights and number of allocations to CPU). Every process in a cluster is assigned the same time slice depending on the weight of its cluster and its CPU service period. The authors performed comparative study of the proposed approach and popular scheduling algorithms on nine groups of processes vary in their attributes. The evaluation was measured in terms of waiting time, turnaround time, and NCS. The experiments showed that the proposed approach gives better results.


Author(s):  
G Siva Nageswara Rao ◽  
N. Srinivasu ◽  
S.V.N. Srinivasu ◽  
G. Rama Koteswara Rao

<p>Process scheduling means allocating a certain amount of CPU time to each of the user processes.  One of the popular scheduling algorithms is the “Round Robin” algorithm, which allows each and every process to utilize the CPU for short time duration.  Processes which finish executing during the time slice are removed from the ready queue.  Processes which do not complete execution during the specified time slice are removed from the front of the queue, and placed at the rear end of the queue. This paper presents an improvisation to the traditional round robin scheduling algorithm, by proposing a new method. The new method represents the time slice as a function of the burst time of the waiting process in the ready queue. Fixing the time slice for a process is a crucial factor, because it subsequently influences many performance parameters like turnaround time, waiting time, response time and the frequency of context switches.  Though the time slot is fixed for each process, this paper explores the fine-tuning of the time slice for processes which do not complete in the stipulated time allotted to them.</p>


2019 ◽  
Vol 17 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Uferah Shafi ◽  
Munam Shah ◽  
Abdul Wahid ◽  
Kamran Abbasi ◽  
Qaisar Javaid ◽  
...  

Central Processing Unit (CPU) is the most significant resource and its scheduling is one of the main functions of an operating system. In timeshared systems, Round Robin (RR) is most widely used scheduling algorithm. The efficiency of RR algorithm is influenced by the quantum time, if quantum is small, there will be overheads of more context switches and if quantum time is large, then given algorithm will perform as First Come First Served (FCFS) in which there is more risk of starvation. In this paper, a new CPU scheduling algorithm is proposed named as Amended Dynamic Round Robin (ADRR) based on CPU burst time. The primary goal of ADRR is to improve the conventional RR scheduling algorithm using the active quantum time notion. Quantum time is cyclically adjusted based on CPU burst time. We evaluate and compare the performance of our proposed ADRR algorithm based on certain parameters such as, waiting time, turnaround time etc. and compare the performance of our proposed algorithm. Our numerical analysis and simulation results in MATLAB reveals that ADRR outperforms other well-known algorithms such as conventional Round Robin, Improved Round Robin (IRR), Optimum Multilevel Dynamic Round Robin (OMDRR) and Priority Based Round Robin (PRR)


2018 ◽  
Vol 7 (4.5) ◽  
pp. 238 ◽  
Author(s):  
Govind Prasad Arya ◽  
Kumar Nilay ◽  
Devendra Prasad

The most important and integral part of a computer system is its operating system. Scheduling various resources is one of the most critical tasks an operating system needs to perform. Process scheduling being one of those tasks, involves various techniques that define how more than one processes can be executed simultaneously. The primary aim here is to the system more efficient and faster. The fundamental scheduling algorithms are: First Come First Serve (FCFS), Round Robin, Priority Based Scheduling, and Shortest Job First (SJF). This paper focuses on Round Robin Scheduling algorithm and various issues related to it. One major issue in RR scheduling is determining the length of Time Quantum. If the Time Quantum is too large RR scheduling behaves as FCFS. On the other hand, if it is too small it forces considerable increase in the number of context switches. Our main objective is to overcome this limitation of traditional RR scheduling algorithm and maximize CPU utilization, further, leading to more efficient and faster system. Here we propose an algorithm that categorizes available processes into High Priority processes and Low Priority process. The proposed algorithm reduces the average waiting time of High Priority processes in all cases and of Low Priority processes in not all but some cases. The overall waiting time changes on the basis of set of processes considered. The simulation results justify that the proposed schemes reduces the overall average waiting time when compared to the existing schemes. 


After studying various CPU scheduling algorithms in Operating System, Round Robin scheduling algorithm is found to be most optimal algorithm in timeshared systems because of the static time quantum that is designated for every process. The efficacy of Round Robin algorithm entirely depends on the static time quantum that is being selected. After studying and analyzing Round Robin algorithm, I have proposed a new modified Round Robin algorithm that is based on shortest remaining burst time which has resulted in dynamic time quantum in place of static time quantum. This improves the performance of existing algorithm by reducing average waiting time and turn-around time and minimizing the number of context switches.


2016 ◽  
Vol 2 (2) ◽  
pp. 19-21
Author(s):  
Achmad Teguh Wibowo

Aspek penting dalam sistem operasi adalah multiprogramming. Multiprogramming adalah proses atau metode yang digunakan untuk mengekssekusi beberapa proses secara bersamaan dalam memori. Tujuan utamanya adalah untuk meminimalkan Average Waiting Time, Average Turnaround Time, dan memaksimalkan penggunaan CPU. Ada berbagai algoritma yang digunakan dalam multiprogramming seperti First Come First Serve (FCFS), Shortest Job First (SJF), Priority Scheduling (PS) dan Round Robin(RR). Diantara semua itu yang paling sering digunakan adalah Round Robin. Round Robin merupakan algoritma penjadwalan yang optimal dengn sistem timeshared. Dalam RR, waktu kuantum bersifat statis dan algoritma ini bergantung pada besarnya kuantum yang dipilih/digunakan. Kuantum inilah yang berpengaruh pada Average Waiting Time dan Average Turnaround Time nantinya. Tujuan dari makalah ini adalah mengusulkan algoritma yang lebih baik daripada Round Robin sederhana dan Smart Optimized Round Robin sebelumnya.


2017 ◽  
Author(s):  
Andysah Putera Utama Siahaan

Task scheduling is needed to maintain every process that comes with a processor in parallel processing. In several conditions, not every algorithm works better on the significant problem. Sometimes FCFS algorithm is better than the other in short burst time while Round Robin is better for multiple processes in every single time. However, it cannot be predicted what process will come after. Average Waiting Time is a standard measure for giving credit to the scheduling algorithm. Several techniques have been applied to maintain the process to make the CPU performance in normal. The objective of this paper is to compare three algorithms, FCFS, SJF, and Round Robin. The target is to know which algorithm is more suitable for the certain process.


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